Memory Reactivation Thaum Kawm Kev Kawm Ib txhij Txhawb Dentate Gyrus/CA2,3 Tus Qauv Sib Txawv Thiab CA1 Memory Integration

Hu rau: Audrey Huaudrey.hu@wecistanche.com

Cov xwm txheej uas sib tshooj nrog cov kev paub dhau los tuaj yeem ua rau rov ua haujlwm ntawm kev nco uas twb muaj lawm. Txawm li cas los xij, qhov kev rov ua kom rov zoo li no yuav muaj qhov txawv txav ntawm qhov tshwm sim hauv hippocampal circuit. Computational theories ntawm hippocampal muaj nuj nqi qhia hais tias dentate gyrus thiab CA2,3 (DG/CA2,3) yog biased rau sib txawv heev zoo nco, whereas CA1 yuav integrate cov xwm txheej cuam tshuam los ntawm sawv cev rau lawv nrog overlapping neural codes. Ntawm no, peb tau sim seb qhov tsim ntawm qhov sib txawv lossis kev sib koom ua ke sawv cev hauv hippocampal subfields nyob ntawm lub zog ntawm kev nco rov ua haujlwm thaum kawm. Tib neeg cov neeg koom nrog kev sib koom ua ke ntawm ob hom kev kawm (AB khub, lub ntsej muag-zoo li los yog scene-shape), thiab tom qab ntawd ua rau fMRI scanning thaum lawv encoded cov koom haum sib tshooj (BC shape-object pairs). Ob qho tib si ua ntej thiab tom qab kev kawm, cov neeg koom kuj tau raug tshuaj xyuas thaum saib cov ntsiab lus tsis ncaj ncees ntawm kev nco sib tshooj (A thiab C cov duab) hauv kev sib cais. Peb siv cov qauv sib txawv los ntsuas los ntsuas qhov rov ua haujlwm ntawm thawj khub nco (A cov khoom) thaum lub sij hawm sib tshooj (BC) kev kawm, nrog rau kev kawm txog kev hloov pauv rau cov ntsiab lus tsis raug cuam tshuam txog kev nco hauv hippocampal subfields. Thaum cov kev nco ua ntej tau rov ua haujlwm zoo thaum lub sijhawm sib tshooj sib tshooj, DG / CA2, 3 thiab subiculum sawv cev rau cov duab tsis ncaj qha (A thiab C) ua tsis zoo sib xws, raws li cov qauv sib txawv. Nyob rau tib lub sijhawm, nco rov ua haujlwm dua thaum kawm tshiab txhawb kev koom ua ke hauv CA1, qhov chaw sawv cev rau cov ntsiab lus tsis raug cuam tshuam txog kev nco tau zoo dua tom qab kawm. Tsis tas li ntawd, lub cim xeeb reactivation thiab subiculum sawv cev tau kwv yees qhov kev txiav txim siab sai thiab muaj tseeb dua (AC). Cov ntaub ntawv no qhia tau hais tias kev rov ua dua ntawm cov kev nco muaj feem xyuam thaum kawm tshiab ua rau cov tswv yim coding tsis sib haum xeeb hauv hippocampal subfields, nyob rau hauv txoj kab nrog kev suav theories.

Ntsiab lus: associative nco; episodic nco; high-resolution fMRI; hippocampal subfield; qauv sib cais

TSEEM CEEB CISTANCHE: Txhim kho nco

Taw qhia

Lub hippocampus yog tsim los ntawm ntau yam subfields uas pab txhawb kev nco thiab sawv cev. Cov qauv kev suav hais tawm hais tias cov khoom siv ntawm cov dentate gyrus thiab CA2,3 (DG / CA2,3) ua rau cov subfields zoo tagnrho rau kev sib cais, los yog kev tsis siv neeg orthogonalization ntawm cortical inputs zoo sib xws los ntawm sparse firing (Marr, 1971; Schapiro li al. ., 2017). Hauv qhov sib piv, cov yam ntxwv ntawm CA1 tau raug npaj los kho kom haum rau kev sib koom ua ke ntawm kev nco lossis kev tsim ntawm cov sawv cev sib tshooj uas tau sau cov yam ntxwv sib xws thoob plaws cov ntu (Eichenbaum li al., 1999; Schlichting and Preston, 2015; Schapiro et al., 2017). Electrophysiological kev tshawb fawb evinces xws li sawv cev dissociations ntawm subfields: DG / CA2,3 ensembles elicit txawv firing qauv nrog tsuas me me kev hloov nyob rau hauv lub perceptual nta ntawm ib puag ncig, whereas CA1 kev ua qauv hloov maj mam raws li ib puag ncig ua perceptually txawv (Leutgeb li al., 200. 2007). Kev ua haujlwm sib luag hauv tib neeg tau pom tias kev hloov pauv hauv DG / CA2,3 qhov kev ua kom pom qhov txawv ntawm cov duab zoo sib xws lossis cov khoom uas sib koom cov ntsiab lus zoo sib xws, thaum CA1 cov lus teb tsis yog (Bakker et al., 2008; Lacy et al., 2011; Dimsdale -Zucker et al., 2018). Subiculum, cov qauv tsim tawm ntawm hippocampal circuit (O'Mara li al., 2001), tuaj yeem ua rau ob qho tib si sib txawv (Potvin li al., 2009) thiab kev sib koom ua ke (Schapiro li al., 2012).

Daim duab 1. Kev sim tsim. Ib tug Schematic ntawm kev coj cwj pwm ua hauj lwm. Cov neeg koom nrog thawj zaug tau nthuav tawm cov duab ntawm tus kheej (lub ntsej muag, scenes, thiab cov khoom tshiab) uas tom qab ntawd yuav dhau los ua kev cuam tshuam ncaj qha los ntawm kev sib koom ua ke (A thiab C yam khoom). Tom qab ntawd, cov neeg koom tau kawm los koom ua ke thawj khub (lub ntsej muag-zoo li lub ntsej muag lossis scene-shape AB koom haum) thiab raug tshuaj xyuas thaum kawm sib tshooj ua ke (cov duab-khoom BC koom haum). Cov neeg koom tau raug tshuaj xyuas dua nyob rau theem tom qab kis thaum lawv saib tib yam khoom los ntawm cov khoom ua ntej (A thiab C). Cov neeg koom nrog tom qab ntawd ua tiav txoj haujlwm hla ib ntus. Thaum kawg, cov neeg koom ua tiav ib txoj haujlwm hauv zos uas lawv tau saib ib tus zuj zus nthuav tawm lub ntsej muag, scenes, khoom, thiab cov duab hauv kev tsim thaiv. B, Visual similarity manipulation. Qhov zoo sib xws ntawm cov khoom B sib koom hla cov khub yog parametrically manipulated. Hauv qhov piv txwv no, cov duab saum toj kawg nkaus yuav tau pom nyob rau hauv thawj zaug AB khub, thaum kab hauv qab sawv cev rau cov duab sib txawv uas tuaj yeem pom thaum kawm sib tshooj BC khub. Cov khoom sib txuas B tau nthuav tawm thaum sib tshooj kev kawm sib tshooj tuaj yeem yog qhov sib tw rau cov khoom B uas tau nthuav tawm thaum pib (AB) khub kev kawm, qhov zoo sib xws lossis qis zoo sib xws morph, lossis cov khoom tshiab (ie, tsis sib tshooj). C, Cov ntsiab lus zoo sib xws ntawm cov duab stimuli siv rau Blinking khoom. Ib qho piv txwv ywj pheej ntawm cov neeg koom ntsuas pom qhov sib xws ntawm cov niam txiv cov duab thiab cov duab morphs nthuav tawm ib sab los ntawm kev siv 5 point Likert scale (1=tsis zoo ib yam, 5=zoo ib yam). pp, 0.05 (paired t-tests). Qhov yuam kev bar qhia 6 SEM.

Txawm li cas los xij, cov haujlwm ua ntej no tsis tau xav txog yuav ua li cas lub cim xeeb reactivation drives dissociable sawv cev cov tswv yim nyob rau hauv lub hippocampus, tso cai rau sawv cev kev kawm mus dhau ib tug yooj yim transformation ntawm sab nraud sensory input thiab nco tso zis. Cov qauv kev kawm suav nrog classic qhia tias cov neeg sawv cev nco yuav tsum tau hloov kho los kwv yees cov txiaj ntsig tau tshwm sim hauv cov lus teb rau ib puag ncig cues, nrog kev sib koom ua ke tshwm sim thaum stimuli kwv yees tib qhov tshwm sim thiab sib txawv thaum stimuli kwv yees cov txiaj ntsig sib txawv (Rumelhart li al., 1986). Txawm li cas los xij, kev tshawb pom fMRI tsis ntev los no qhia tias kev sib txawv kuj tuaj yeem tshwm sim thaum stimuli sib koom ua ke los yog cov txiaj ntsig (Schlichting li al., 2015; Favila et al., 2016; Zeithamova et al., 2018). Nyob rau hauv cov kev tshawb fawb no, hippocampal sawv cev muaj ntau qhov txawv rau stimuli uas sib koom ib qho tshwm sim ntau dua li stimuli nrog cov txiaj ntsig sib txawv. Qhov kev sib txawv no tsis tuaj yeem piav qhia nyob rau hauv cov nqe lus ntawm kev sib cais tsis siv neeg ntawm cov tswv yim sab nraud los ntawm kev sib cais coding hauv DG/CA2,3; theoretical foundations tsis ntev los no qhia tias kev nco rov ua haujlwm tuaj yeem suav txog yuav ua li cas hippocampal cov sawv cev hloov pauv hauv lub ntsej muag ntawm cov xwm txheej sib tshooj (Ritvo li al., 2019).

Raws li qhov kev xav no, kev kawm zoo txo ​​qis kev sib tw ntawm kev nco los ntawm kev sib txawv lossis kev sib koom ua ke (Ritvo li al., 2019). Txawm hais tias kev hnov ​​​​lus sib tshooj hauv ib puag ncig yog ib qho tseem ceeb uas yuav ua rau muaj kev pom zoo sawv cev uas txo qhov tsis meej pem (Leutgeb li al., 2004, 2007; Lacy li al., 2011; Yassa thiab Stark, 2011), dab tsi yuav yog qhov tseem ceeb tshaj. yog li cas overlapping sensory input drives reactivation ntawm kev sib tw nco. Reactivated nco yuav yog "lub hom phiaj" ntawm kev kawm ntau dua li cov yam ntxwv ntawm kev hnov ​​​​qab uas ua rau rov ua haujlwm dua. Yog li, hauv txoj kev tshawb fawb tam sim no, peb tau mus dhau qhov kev xav txog qhov zoo sib xws li tus neeg tsav tsheb ntawm hippocampal sawv cev thiab kuaj seb puas muaj kev cuam tshuam txog kev nco qab hauv lub cortex thaum kawm tau tshwm sim hauv kev sib cais sub-field coding. Peb xav tias kev nco rov ua haujlwm yuav raug hloov kho los ntawm qhov xwm txheej zoo sib xws thoob plaws kev kawm (Vieweg et al., 2015) thiab yog li yuav yog qhov tseem ceeb ntawm kev kho kom haum rau qib ntawm kev sawv cev sib tshooj tau pom rau cov xwm txheej zoo sib xws hauv hippocampal subfields (Ritvo li al., 2019). Peb kuj tau xav tias kev sib koom ua ke thiab kev sib txawv yuav tsis yog cov txiaj ntsig ntawm kev sib koom ua ke hauv kev teb rau lub cim xeeb rov ua haujlwm, tab sis qhov kev rov ua kom rov ua tau zoo dua yuav ua rau muaj kev sib koom ua ke ntawm kev sib koom ua ke sib txawv thiab sib koom ua ke sawv cev hauv DG / CA2,3 thiab CA1.

Txhawm rau ntsuas cov kev kwv yees, peb parametrically manipulated perceptual zoo sib xws ntawm overlapping txheej xwm nyob rau hauv ib tug associative inference hauj lwm (Fig. 1). Cov neeg koom nrog tau kawm thawj khub thiab raug tshuaj xyuas siv fMRI kev daws teeb meem thaum kawm cov khub sib tshooj. Peb tau soj ntsuam kev nco rau cov khub kawm thiab inferred kev paub ntawm indirect kev sib raug zoo nyob rau hauv cov khub, nrog inference kev ua tau zoo pab raws li ib tug cwj pwm Performance index ntawm kev koom ua ke (Shohamy thiab Wagner, 2008; Zeithamova li al., 2012). Qhov tseem ceeb, peb suav tias yuav ua li cas nco reactivation thaum sib tshooj kev kawm cuam tshuam rau hippocampal subfield sawv cev

KEV PAB CUAM CISTANCHE SUPPLEMENT: Txhim kho nco

Cov ntaub ntawv thiab cov txheej txheem

Cov neeg koom nrog Peb caug-ob tus neeg sab xis (15 tus poj niam, hnub nyoog 18-31} xyoo, txhais tau tias=21.5 xyoo) tau koom nrog tom qab tau txais kev tso cai pom zoo raws li txoj cai pom zoo los ntawm Pawg Saib Xyuas Kev Tshawb Fawb hauv University of Texas ntawm Austin. Cov neeg koom tau txais $ 25 / teev hauv kev them nyiaj. Cov ntaub ntawv los ntawm 6 tus neeg koom tau raug tshem tawm los ntawm kev tshuaj ntsuam: 2 tus neeg koom vim yog lub taub hau ntau dhau, 1 tus neeg koom nrog uas tau thim tawm ntawm qhov kev sim, 2 tus neeg koom nrog cov kev tshawb xyuas tsis tiav (cov kev tshawb fawb tom qab thiab / lossis cov theem hauv zos tsis tau txheeb xyuas), thiab 1 tus neeg koom rau duab artifacts nyob rau hauv lub functional scans uas precluded tsom xam ntawm lub preexposure thiab localizer theem. Cov neeg koom nrog (n=26, 14 tus poj niam) tau suav nrog hauv kev tshuaj ntsuam. Peb tau txiav txim siab peb cov qauv zaum kawg raws li cov kev tshawb fawb muaj feem xyuam uas siv cov qauv zoo sib xws thiab kev tshuaj ntsuam xyuas (Zeithamova li al., 2012; Schlichting li al., 2015; Dimsdale-Zucker li al., 2018). Tsis tas li ntawd, qhov piv txwv loj no tau muab rau peb qhov kwv yees kwv yees lub zog ntawm .0.99 txhawm rau txheeb xyuas qhov cuam tshuam ntawm qhov pom kev zoo sib xws ntawm qhov kev txiav txim siab thoob plaws qhov tseeb raws li cov ntaub ntawv tsav tsheb los ntawm ib pawg neeg koom (n=30, 22 tus poj niam, hnub nyoog { {23}} xyoo, txhais tau tias=18.9 xyoo; rov qab ntsuas ANOVA ua rau ib nrab h squared (h2 )=0.280).

Stimuli yog 58 lub ntsej muag tsis paub (ib nrab txiv neej, ib nrab poj niam, tag nrho cov neeg dawb), 58 qhov tsis paub zoo (ib nrab ntuj, ib nrab neeg tsim), 671 cov duab dub tsim hauv MATLAB (yog xav paub ntxiv, saib Visual zoo sib xws manipulation thaum lub sij hawm encoding tshiab), thiab 74 tshiab khoom (Hsu et al., 2014; Schlichting et al., 2015). Ib pawg ntawm cov stimuli tau npaj rau hauv 32 triads uas muaj peb yam khoom (A, B, C) uas tau siv rau hauv kev ua haujlwm sib koom ua ke (Fig. 1A). Cov khoom A muaj ntsej muag (16) sib npaug sib cais los ntawm poj niam txiv neej, thiab scenes (16) sib npaug sib cais los ntawm ntuj thiab tib neeg; tag nrho cov khoom B yog cov duab (56); tag nrho cov khoom C yog cov khoom tshiab (32). Lwm sub-set ntawm stimuli (42 lub ntsej muag, 42 scenes, 42 yam khoom, thiab 42 duab) tau siv nyob rau hauv lub localizer txoj hauj lwm thiab tsis tau pom thaum lub associative inference hauj lwm. Kev ua haujlwm ntawm stimuli rau triads thiab localizer ua haujlwm tau randomized thoob plaws cov neeg koom. Stimuli tau nthuav tawm siv Psychtoolbox hauv MATLAB (Brainard, 1997; Pelli, 1997; Kleiner li al., 2007).

Task Procedure Initial Pair (AB) kev kawm. Cov neeg koom nrog tau kawm thawj khub (AB) hla plaub qhov kev tshawb nrhiav-kev sim ntsuas. Thaum lub sijhawm kawm, txhua tus ntawm 32 thawj khub tau nthuav tawm rau 3.5 s nrog rau 0.5 s intertrial interval (ITI). Cov khoom A (lub ntsej muag lossis qhov chaw) ib txwm nthuav tawm ntawm sab laug, thiab B yam (zoo li) yeej ib txwm nthuav tawm ntawm sab xis. Tom qab kawm tag nrho cov khub, cov neeg koom tau raug sim siv 3- lwm txoj kev xaiv yuam kev. Cov neeg koom nrog tau txais cov khoom A nyob rau sab saum toj ntawm qhov screen thiab yuav tsum xaiv ntawm qhov tsim nyog B yam khoom thiab ob daim foils. Cov foils yog cov duab los ntawm lwm cov triads, xws li cov neeg tuaj koom tsis tuaj yeem pib lawv qhov kev txiav txim siab ntawm qhov paub txog cov duab. Cov neeg koom nrog muaj 10 s los teb rau txhua qhov kev sim. Tom qab tus neeg koom nrog cov lus teb, cov lus pom zoo tau muab thaum kawg ntawm txhua qhov kev sim rau 1 s. Kev sim ntsuas tau sib cais los ntawm 0.5 s ITI. Cov duab anatomical tau sau thaum lub sijhawm no.

Kev pom zoo sib xws manipulation thaum tshiab encoding. Txhawm rau tshuaj xyuas seb qhov zoo sib xws ntawm cov xwm txheej cuam tshuam li cas rau lub cim xeeb rov ua haujlwm thiab coj tus cwj pwm, qhov pom kev zoo sib xws ntawm cov khoom sib txuas (cov duab, lossis B yam khoom) hauv kev sib koom ua haujlwm inference yog parametrically manipulated (Fig. 1B). Peb tswj kev pom kev zoo sib xws raws li kev ua haujlwm ua ntej uas qhia tias cov lus teb hippocampal subfield tau hloov kho los ntawm qhov pom kev sib tshooj ntawm cov xwm txheej (Leutgeb li al., 2004, 2007; Bakker et al., 2008; Lacy et al., 2011). Muaj tag nrho plaub yam xwm txheej: kev sib tw tiag tiag, zoo sib xws, qis zoo sib xws, thiab tshiab. Hauv kev sib tw tiag tiag, cov neeg koom pom qhov sib txuas sib txuas B zoo li thaum kawm thawj khub (AB) thiab cov khub sib tshooj (BC). Nyob rau hauv qhov siab thiab qis zoo sib xws, txhua tus duab pom hauv cov khub sib tshooj yog qhov parametric morph ntawm cov duab los ntawm ib qho ntawm thawj khub. Cov duab "niam txiv" tau tsim los ntawm kev noj 16 cov ntsiab lus muab faib raws ib puag ncig ntawm lub voj voog, random txhais txhua qhov taw tes, thiab tom qab ntawd txuas cov ntsiab lus nyob ib sab los tsim cov npoo siv spline interpolation. Cov duab nyob rau hauv qhov siab thiab qis zoo sib xws tau tsim los ntawm kev noj ob-niam txiv duab thiab nruab nrab ntawm cov kev sib koom ua ke ntawm cov vertices siv qhov hnyav sib txawv. Cov duab zoo sib xws tau hnyav 80 feem pua ​​​​rau ib leej niam leej txiv thiab 20 feem pua ​​​​rau lwm tus niam txiv, thaum cov duab tsis zoo sib xws tau hnyav 70 feem pua ​​​​rau ib tus niam txiv thiab 30 feem pua ​​​​rau lwm tus. Nyob rau hauv qhov xwm txheej tshiab, cov neeg koom pom cov duab tshiab ua ke nrog cov khoom tshiab, ua rau cov khub no tsis sib haum nrog thawj khub. Cov khub tshiab yog li no ua lub hauv paus rau kev kawm sib koom. Txhua tus neeg koom tau kawm txog yim triads ib qho kev pom zoo sib xws.

Qhov sib txawv ntawm cov ntsiab lus zoo sib xws ntawm cov khoom sib xws siab thiab qis tau lees paub hauv cov qauv ywj pheej ntawm 9 tus neeg koom (8 tus poj niam, hnub nyoog 18-22 xyoo, txhais tau tias=19.4 xyoo). Cov neeg koom nrog hauv cov qauv no tau ntsuas qhov pom kev zoo sib xws ntawm niam txiv cov duab thiab cov duab morphs nthuav tawm ib sab los ntawm kev siv 5 point Likert scale (1=tsis zoo ib yam, 5=zoo sib xws heev) hla 180 kev sim . Cov kev sib tw tiag tiag tau raug ntsuas raws li qhov zoo sib xws ntau dua li qhov sib xws siab morphs (t(8) {{10}}.255, p , 0.001, Cohen's d=2.085), siab zoo sib xws morphs raug ntsuas raws li qhov zoo sib xws tshaj li qhov tsis zoo sib xws morphs (t(8)=9.312, p , 0.001, d=3.104), thiab qis zoo sib xws morphs raug ntaus nqi ntau dua li qhov tshiab yam (t(8)=10.021, p, 0.001, d=3.340). Ib qho kev ceeb toom rau kev txheeb xyuas qhov zoo sib xws uas siv txoj hauv kev no yog qhov kev sib piv tsis suav nrog lub cim xeeb. Nws muaj peev xwm hais tias, yog tias peb tso qhov ncua sij hawm ntawm qhov kev nthuav qhia ntawm ob daim duab, qhov kev pom zoo sib xws muaj nuj nqi (Fig. 1C) tej zaum yuav txawv; Piv txwv li, qhov sib txawv ntawm qhov sib txawv ntawm qhov siab thiab qhov tsis zoo sib xws tej zaum yuav muaj tsawg dua. Txawm hais tias qhov ntsuas qhov ntsuas no tuaj yeem cuam tshuam rau kev txhais lus ntawm kev txiav txim siab zoo sib xws ntawm lawv tus kheej, nws tsis tshua muaj kev cuam tshuam rau kev txhais lus ntawm peb lub hauv paus kev coj cwj pwm thiab kev ntsuam xyuas neural. Peb soj ntsuam qhov sib txawv hauv kev ua haujlwm nco thiab rov ua haujlwm ntawm qhov zoo sib xws (nrog rau cov xwm txheej siab thiab qis) uas qhia txog plaub qhov kev sib txawv ntawm qhov sib txawv cuam tshuam rau kev ua haujlwm (saib Cov txiaj ntsig). Tsis tas li ntawd, peb qhov kev ntsuam xyuas neural ntsuam xyuas qhov kev hloov pauv ntawm cov neeg sawv cev ntawm qhov kev hloov pauv tau tsom mus rau qhov zoo sib xws nkaus xwb thiab tsis txhob cia siab rau kev sib piv rau lwm yam zoo sib xws (saib Kev Tshaj Tawm ntawm cov khoom ua ntej thiab tom qab kawm).

Overlapping khub (BC) kev kawm. Tom qab cov neeg koom tau kawm thawj khub, lawv tau tshuaj xyuas thaum kawm cov khub sib tshooj. Cov theem no dua muaj plaub qhov kev kawm-test blocks. Thaum lub sijhawm kawm theem, 32 khub tau nthuav tawm siv qhov kev tshwm sim ntsig txog kev tsim, nrog cov khub nthuav tawm rau 3.5 s ua raws li 8.5 s ITI ntawm kev kho. Cov khoom C (khoom) yeej ib txwm nthuav tawm ntawm sab laug, thiab cov khoom B (puab) yeej ib txwm nthuav tawm ntawm sab xis. Tom qab txhua theem kev kawm, cov neeg koom tau raug sim ntawm BC khub uas siv 3- lwm txoj kev xaiv yuam kev, uas tsis tau tshuaj xyuas. Cov neeg koom nrog tau txais cov khoom C nyob rau sab saum toj ntawm qhov screen thiab yuav tsum tau xaiv ntawm qhov tsim nyog B yam khoom thiab ob daim foils. Cov lus teb tsis tau muab rau lub sijhawm no. Cov neeg koom nrog muaj 10 s los teb rau txhua qhov kev sim, thiab kev sim sib cais los ntawm 0.5 s ITI.

Kev nthuav tawm ntawm tus kheej cov khoom ua ntej thiab tom qab kawm. Ua ntej kawm thawj khub niam txiv thiab tom qab kawm cov khub sib tshooj, cov neeg koom tau nthuav tawm cov khoom A thiab C ntawm tus kheej (lub ntsej muag, scenes, thiab cov khoom) los ntawm cov xwm txheej zoo sib xws. Cov theem raug raug txwv rau ib qho kev pom zoo sib xws kom ua kom muaj ntau qhov kev nthuav qhia rau txhua qhov kev txhawb nqa thiab txhim kho kev kwv yees ntawm cov qauv kev ua haujlwm ntsig txog kev ua haujlwm (saib Kev kwv yees ntawm tus kheej cov qauv kev txhawb nqa ua ntej thiab tom qab kawm). Siv ib qho xwm txheej zoo sib xws kuj tso cai rau peb tswj hwm qhov cuam tshuam ntawm qhov pom kev zoo sib xws thaum xam cov kev hloov pauv hloov. Qhov pom kev zoo sib xws tau siv vim tias ua ntej ua haujlwm hauv tib neeg tau pom tias qhov pom kev zoo sib xws tau cuam tshuam cov lus teb sib txawv hauv DG / CA2,3 thiab CA1 (Lacy li al., 2011).

Hauv txhua qhov kev sib kis, cov neeg koom tau raug tshuaj xyuas thaum cov khoom raug nthuav tawm rau 1 s nrog 3 s ITI. Thaum txhua yam khoom nyob rau ntawm qhov screen, cov neeg koom ua tiav qhov kev hloov pauv kev tshawb nrhiav los ntawm kev qhia ntawm lub pob nyem seb puas muaj tus ntoo khaub lig superimposed dub hloov xim rau ntsuab lossis xiav 100-200 ms tom qab stimulus pib (Kriegeskorte li al., 2008; Schlichting et ib., 2015). Muaj plaub qhov kev rov ua dua ntawm txhua yam ntawm ib qho kev khiav, thiab tag nrho ntawm plaub qhov kev khiav txhua qhov hauv preexposure thiab postexposure theem. Kev sim tau pseudorandomized xws li cov khoom nyob rau hauv ib qho triad tau nthuav tawm nrog tsawg kawg ob yam khoom sib cuam tshuam los ntawm lwm cov triads. Tsis tas li ntawd, 20 feem pua ​​​​ntawm cov kev sim no tsis muaj tseeb (piv txwv li, tsis muaj qhov khoom lossis kev hloov pauv kev ua haujlwm) los txhim kho cov khoom-qib kev kwv yees hauv kev tshuaj xyuas; cov kev sim null no tau muab tso rau hauv qhov sib txawv ntawm cov khoom nthuav qhia kev sim. Kev txiav txim mus sib hais thiab lub sij hawm tau zoo ib yam nyob rau hauv preexposure thiab postexposure theem. Qhov tseeb ntawm txoj haujlwm tshawb nrhiav kev hloov pauv tau raug saib xyuas kom ntseeg tau tias cov neeg koom tes tau ua tib zoo saib xyuas cov haujlwm tab sis tsis suav tias yog ntxiv.

Kuj tseem muaj qhov tsis raug kuaj pom ua ntej rau cov khoom los ntawm qhov sib tw tiag tiag, qhov tsis zoo sib xws, thiab cov xwm txheej tshiab uas tshwm sim ua ntej thawj zaug scanned preexposure khiav. Lub hom phiaj ntawm theem no yog kom sib npaug ntawm cov khoom A thiab C hauv qhov kev sib tw tiag tiag, qhov tsis zoo sib xws, thiab cov xwm txheej tshiab rau cov khoom hauv qhov zoo sib xws ua ntej ua khub kawm. Qhov tsis raug tshuaj ntsuam xyuas tau zoo ib yam li cov theem raug kuaj pom, tshwj tsis yog ITI yog 0.5 s thiab tsis muaj kev sim siab.

Associative inference (AC) xeem. Tom qab lub sijhawm dhau los, cov neeg koom tau muab qhov kev sim siab ntawm kev sib raug zoo ntawm cov khoom A thiab C uas sib koom ua ke (B). Qhov kev ntsuam xyuas inference tau ua nyob rau hauv lub scanner tab sis tsis tau scanned. Nyob rau theem no, cov neeg koom tau raug suav nrog C yam khoom (khoom) thiab tuaj yeem xaiv ntawm A yam khoom ntawm tib qeb (piv txwv li, peb lub ntsej muag lossis peb qhov xwm txheej). Hauv kev sim ntsej muag, cov neeg koom tau raug qhia kom xaiv tus neeg uas feem ntau yuav yog tus tswv ntawm cov khoom cued. Ntawm qhov kev sim sim, lawv tau raug qhia kom xaiv qhov chaw uas lawv yuav pom qhov khoom cued. Tseem ceeb heev, tsis muaj ib qho taw tes uas cov neeg koom tau qhia meej meej txog qhov pom kev zoo sib xws los yog kev sib tshooj ntawm kev kawm. Cov neeg koom tau muab 10 s los teb. Tsis muaj lus teb tau muab.

Localizer. Tom qab qhov kev xeem inference, cov neeg koom tau raug tshuaj xyuas hauv ib qho haujlwm hauv zos. Hauv txoj haujlwm no, cov neeg koom tau saib ntau yam kev txhawb nqa los ntawm plaub yam kev txhawb nqa uas siv hauv kev sim: ntsej muag, scenes, duab, thiab khoom. Stimuli tau nthuav tawm hauv cov qauv tsim, nrog rau txhua qhov thaiv muaj yim cov duab nthuav tawm rau 2.5 s txhua tus nrog 0.5 s ITI. Thaum lub sij hawm txhua qhov stimulus thaiv, cov neeg koom ua tiav ib qho kev nco rov qab ua haujlwm uas lawv yuav tsum tau kuaj xyuas qhov kev txhawb nqa rov qab. Muaj ib qho kev rov ua dua tshiab hauv txhua qhov thaiv. Qhov tseeb ntawm kev ua haujlwm ib-rov qab tau raug saib xyuas kom ntseeg tau tias cov neeg koom tes tau ua tib zoo saib xyuas cov haujlwm tab sis tsis raug txiav txim siab ntxiv. Blocks tau sib cais los ntawm 8 s ntawm fixation. Cov neeg koom ua tiav peb qhov kev khiav haujlwm hauv zos, nrog ob qhov thaiv ib hom kev txhawb nqa ib qho kev khiav.

fMRI cov ntaub ntawv sau thiab cov ntaub ntawv ua ntej tau sau nrog 3T Siemens Skyra. Muaj tag nrho ntawm 15 kev ua haujlwm scans (TR=2000 ms, TE=30} ms, ntxeev lub kaum sab xis=73} degree, 1.7 hli isotropic voxels, EPI, multiband acceleration factor=3) nyob rau hauv preexposure, overlapping khub kawm, postexposure, thiab localizer theem. Peb daim duab qhia chaw (TR=589} ms, TE=5 ms/7.46 ms, 1.5 1.5 2 mm voxels, ntxeev lub kaum sab xis=5 degree ) tau sau los kho qhov tsis sib haum xeeb hauv qhov sib nqus: ib qho tam sim ntawd ua ntej lub preexposure theem los kho cov preexposure scans, ib tug ua ntej lub overlapping khub kawm theem kho cov kev tshawb fawb thiab postexposure scans, thiab ib tug ua ntej lub localizer theem los kho cov localizer scans. AT1- hnyav 3D MPRAGE ntim tau sau (TR {{20}}} ms, TE=2.43 ms, ntxeev lub kaum sab xis=9 degree, 1 hli isotropic voxels) txhawm rau pab txhawb kev sib raug zoo thiab normalization ntawm cov ntaub ntawv ua haujlwm rau tus qauv anatomic. Ob lub coronal T2- nyhav structural scans, aligned perpendicular rau hippocampal ntev axis, tau sau (TR=13,150 ms, TE=82 ms, 0.4 mm 0.4 mm nyob rau hauv dav hlau, 1.5 hli los ntawm-plane) thiab ces nruab nrab rau subfield segmentation.

Kev ua haujlwm thiab cov duab anatomic tau ua ntej siv FMRIB Software Library version 5.0.9 (FSL: http://fsl.fmrib.ox.ac.uk/fsl/) thiab Advanced Normalization Tools (ANTS) version 2.1 ( Avants et al., 2011). Kev soj ntsuam ua haujlwm tau raug kho kom raug siv MCFLIRT hauv FSL thiab tom qab ntawd sau npe mus rau qhov kev sib tshooj zaum kawg ua haujlwm uas siv affine transformations hauv ANTS. Cov qauv nonbrain raug tshem tawm los ntawm kev soj ntsuam ua haujlwm thiab MPRAGE siv BET hauv FSL. Kev ua cov ntaub ntawv ntxiv tau ua los ntawm FEAT (FMRI Kws Tshawb Fawb Kev Tshawb Fawb) version 6.00, ib feem ntawm FSL. Cov kev txheeb cais hauv qab no tau siv rau tag nrho cov duab ua haujlwm; kev sib koom ua ke nrog MPRAGE thiab daim duab qhia chaw-raws li EPI unwarping siv FUGUE (Jenkinson, 2003); grand-mean siv normalization ntawm tag nrho 4D dataset los ntawm ib qho kev sib txuam ntau; high-pass temporal filtering (Gaussian-qhov hnyav tsawg-squares ncaj-kab haum, nrog s=64 s). Spatial smoothing siv Gaussian kernel ntawm FWHM 4 mm tau siv rau qhov sib tshooj ntawm kev kawm thiab hauv zos scans.

ROIs Anatomical ROIs suav nrog tag nrho lub hlwb grey teeb meem rau kev tsom xam reactivation thiab hippocampal subfields rau kev tsom xam neural coding. Lub ntsej muag grey tag nrho lub hlwb tau tsim rau txhua tus neeg koom nrog hauv ib qho chaw siv FAST (Zhang li al., 2001), ib feem ntawm FSL, nrog MPRAGE. Grey teeb meem qhov ncauj qhov ntswg tau raug hloov mus rau hauv kev daws teeb meem uas siv cov kev hloov pauv hauv ANTS. Nyob rau hauv lub hippocampus, ua kom cov qauv hauv subfields CA1, ib tug ua ke DG/CA2,3 cheeb tsam, thiab subiculum tau soj ntsuam. Hippocampal subfields tau txheeb xyuas nyob rau hauv lub taub hau thiab lub cev ntawm hippocampus nyob rau hauv haiv neeg qhov chaw los ntawm rov qab normalizing lub qhov ncauj qhov ntswg los ntawm ib tug qhib-qhov template nrog segmented subfields (Schlichting li al., 2019) mus rau qhov nruab nrab T2 coronal duab ntawm txhua tus neeg koom siv uas tsis yog-linear SyN transformations nyob rau hauv ANTS. Cov txheej txheem no tau pom tias muab cov txiaj ntsig zoo piv rau phau ntawv taug qab (Schlichting li al., 2019). Lub qhov ncauj qhov ntswg tau raug tshuaj xyuas thiab kho manually rau txhua tus neeg koom tes kom tshem tawm cov voxels sab nraum lub hippocampus thiab xyuas kom meej segmentation raws li cov txheej txheem tsim (West thiab Gundersen, 1990; Duvernoy, 1998; Mai et al., 2007). Thaum kawg, lub qhov ncauj qhov ntswg subfield tau hloov mus rau qhov chaw ntawm kev ua haujlwm scans los ntawm thawj zaug sau npe nruab nrab ntawm cov duab coronal rau MPRAGE siv cov kev hloov pauv thiab tom qab ntawd siv cov kev hloov pauv yav dhau los rau qhov chaw ua haujlwm.

TSEEM CEEB CISTANCHE EXTRACT: Txhim kho nco

Quantification thiab statistical tsom xam

Decoding nco reactivation thaum sib tshooj kev kawm. Txhawm rau ntsuas qhov rov ua haujlwm ntawm cov qauv encoding ntsig txog cov thawj khub thaum sib tshooj ntawm kev kawm, peb tau siv cov qauv kev txheeb cais hauv PyMVPA (Hanke li al., 2009). Yog tias cov neeg koom nrog rov qhib cov ntaub ntawv ntsig txog (xws li, A lub ntsej muag thiab cov khoom tshwm sim los ntawm AB khub) thaum kawm sib tshooj ua ke (BC zoo li-khoom khub), ces tus qauv cais tawm ntawm cov ntaub ntawv hauv cheeb tsam yuav tsum tau nkag siab rau qeb ntawm cov ntaub ntawv (txawm lub ntsej muag lossis scene) uas yog reactivated (Polyn li al., 2005; Kuhl et al., 2011; Zeithamova et al., 2012). Yog li, peb tau cob qhia tus qauv classifier nrog cov ntaub ntawv los ntawm lub localizer theem thiab tom qab ntawd siv cov classifier mus rau lub overlapping khub kawm theem. Peb ua haujlwm ua haujlwm nco rov ua haujlwm raws li cov ntaub ntawv pov thawj rau qeb ntawm cov khoom A (piv txwv li, lub ntsej muag lossis qhov chaw) los ntawm thawj khub AB ntsig txog cov sib tshooj BC.

Peb ntsuas nco reactivation siv tus txheej txheem multistep. Ua ntej, peb tau khiav tag nrho lub hlwb tshawb nrhiav (Kriegeskorte et al., 2006) txhawm rau txheeb xyuas cov cheeb tsam uas cov ntaub ntawv hais txog A cov khoom raug muab rov qab rau hauv kev sib tshooj sib tshooj. Nyob rau hauv txhua qhov kev tshawb nrhiav lub ntsej muag (lub vojvoog=3 voxels, ntim=123 voxels), ib qho kev txhawb nqa vector tshuab tau raug cob qhia kom sib txawv cov qauv neural los ntawm cov theem hauv cheeb tsam cuam tshuam nrog lub ntsej muag, scenes, khoom, thiab cov duab. Txhawm rau suav rau hemodynamic lag, txhua daim duab ua haujlwm tau sau los ntawm kev siv cov ntawv sim thiab lub sijhawm hloov mus rau pem hauv ntej los ntawm 4 s (ob TRs). Cov kev kawm tau kawm tau raug siv rau cov qauv neural los ntawm qhov sib tshooj ntawm cov khub kawm, uas kuj tau hloov sijhawm los ntawm 4 s. Kev ntsuas theem rov ua dua tshiab tau muab rho tawm los ntawm kev siv cov pov thawj cais rau pawg uas cuam tshuam nrog A yam khoom ntawm txhua qhov triad (piv txwv li, cov ntaub ntawv pov thawj rau lub ntsej muag rau lub ntsej muag-zoo li cov khoom triads) rau ob TRs sib haum rau kev nthuav qhia ntawm txhua khub. Cov ntaub ntawv pov thawj muaj txiaj ntsig tau muab faib ua ob pawg: cov txheej txheem rov ua dua tshiab thiab cov txheej txheem pib. Cov txheej txheem reactivation muaj cov ntaub ntawv pov thawj muaj txiaj ntsig los ntawm qhov tseeb match, siab zoo sib xws, thiab kev sim tsis zoo sib xws. Cov txheej txheem hauv paus muaj lub ntsej muag thiab cov pov thawj pov thawj qhov tseem ceeb los ntawm kev sim hauv qhov xwm txheej tshiab. Vim hais tias cov duab-khoom khub nyob rau hauv cov xwm txheej tshiab tsis sib tshooj nrog ib qho ntawm cov khub uas tau kawm yav dhau los, lawv yuav tsum tsis txhob cuam tshuam rov ua dua lub ntsej muag lossis qhov chaw nco. Qhov kawg reactivation index yog xam nyob rau hauv txhua tus kheej los ntawm kev noj qhov sib txawv ntawm qhov nruab nrab cov pov thawj rau lub reactivation teem thiab qhov nruab nrab ntawm lub hauv paus txheej txheem.

Txhawm rau ntsuas qhov tseem ceeb ntawm qhov ntsuas qhov ua kom rov ua haujlwm no, peb muab piv rau qhov ntsuas qhov ua kom rov ua haujlwm tiag tiag rau qhov tsis muaj kev faib tawm hauv txhua qhov kev tshawb nrhiav qhov chaw. Qhov kev faib tawm null tau tsim dua 1000 iterations los ntawm shuffling classifier pov thawj muaj nuj nqis nyob rau hauv reactivation thiab baseline sets thiab tom qab ntawd xam cov reactivation Performance index txhua iteration. Qhov nruab nrab voxel ntawm txhua qhov kev tshawb nrhiav lub ntsej muag tau tshaj tawm qhov kev faib ua feem ntawm qhov tsis muaj kev faib tawm nrog cov ntsuas reactivation ntau dua lossis sib npaug rau qhov ntsuas pom kev rov ua haujlwm (piv txwv li, p-tus nqi). Txhawm rau txheeb xyuas thaj chaw reactivation thoob plaws cov neeg tuaj koom, ib tus neeg koom nrog daim ntawv qhia kev tshawb nrhiav teeb pom kev zoo li qub rau ib pawg qauv rau kev ntsuas qhov tseem ceeb. Cov duab p-value tau hloov mus rau z-statistic dluab thiab tom qab ntawd warped rau MNI 152 anatomic template (resampled rau qhov kev daws teeb meem ntawm kev ua haujlwm scans, 1.7 mm isotropic voxels) siv cov nonlinear SyN transformations hauv ANTS. Voxelwise, nonparametric permutation kuaj tau ua tiav siv Randomise hauv FSL tshaj 5000 iterations (Winkler li al., 2014). Cov pawg tseem ceeb tau raug txheeb xyuas los ntawm kev siv lub voxel qhov pib ntawm p, 0.01 (tsis raug kho) thiab pawg pib ntawm p, 0.05. Cov theem pib tau suav nrog siv AFNI (Cox, 1996) ua haujlwm 3dClustSim nrog kev kwv yees smoothness tau los ntawm kev kawm theem uas siv 3dFWHMx raws li spatial AutoCorrelation Function. Kev sib koom ua ke tau txiav txim siab los ntawm kev siv ob-sided thresholding nrog qhov thib ob-nyob ze cov neeg zej zog pawg.

Txhawm rau kom paub meej tias qhov kev ntsuas rov ua haujlwm tsis tau tsav los ntawm ib pawg kev txhawb nqa, peb txuas ntxiv nug cov teeb pom kev zoo los kuaj seb puas rov ua haujlwm tau hloov pauv nrog pawg stimulus (lub ntsej muag lossis scene) ntawm A yam khoom hauv kev soj ntsuam tom qab hoc. Cov pawg tseem ceeb uas tau txheeb xyuas hauv qhov kev tshawb nrhiav lub teeb pom kev rov ua haujlwm tau hloov mus rau binary lub qhov ncauj qhov ntswg thiab thim rov qab-zoo li qub rau hauv qhov chaw ib txwm siv ANTS. Tom qab ntawd, qhov kev tshuaj xyuas rov ua dua tau rov ua dua hauv txhua qhov kev ua haujlwm ROI rau txhua tus neeg koom. Peb tau siv rov ntsuas dua ANOVA nrog rau cheeb tsam thiab pawg txhawb nqa raws li cov xwm txheej los ntsuas seb puas rov ua haujlwm dua hauv txhua cheeb tsam txawv raws li kev ua haujlwm ntawm pawg txhawb nqa.

Thaum peb qhov kev tshawb nrhiav pom thawj zaug hauv cheeb tsam hauv cheeb tsam uas rov ua haujlwm tau tshwm sim saum lub hauv paus, peb kuj tau khiav ib qho kev tshawb nrhiav ywj pheej los txheeb xyuas cov cheeb tsam uas rov ua kom muaj zog sib txawv nrog kev pom zoo sib xws. Qhov kev tshawb nrhiav no tau siv txoj hauv kev zoo sib xws rau kev tshuaj ntsuam ntsuas tag nrho cov kev rov ua haujlwm, tab sis nrog rau qib ntxiv uas piv cov pov thawj cais rau kev rov ua dua ntawm qhov tseeb match thiab lwm yam zoo sib xws (piv txwv li, qhov zoo sib xws thiab qhov tsis zoo sib xws). Cov txiaj ntsig ntawm qhov zoo sib xws tau suav rau hauv txhua tus kheej los ntawm kev siv qhov sib txawv ntawm qhov nruab nrab cov pov thawj rau qhov tseeb match thiab cov pov thawj nruab nrab rau qhov siab thiab qis zoo sib xws. Qhov sib txawv no tau muab piv nrog rau qhov tsis muaj kev faib tawm hauv txhua qhov kev tshawb nrhiav lub ntsej muag, uas tau tsim ntau dua 1000 iterations los ntawm kev sib tsoo cov ntaub ntawv pov thawj muaj txiaj ntsig thoob plaws qhov sib tw tiag tiag thiab qhov zoo sib xws morph cov xwm txheej. Normalization rau pawg qauv, kev ntsuas kev txheeb cais, thiab kev kho pawg yog zoo ib yam rau lub teeb pom kev txheeb xyuas qhov rov ua haujlwm saum toj saud.

Kev kwv yees ntawm tus kheej stimulus qauv ua ntej thiab tom qab kawm. Peb tau txais kev kwv yees ntawm neural activation qauv elicited los ntawm txhua tus ntawm A (lub ntsej muag, scenes) thiab C (novel 3D khoom) stimuli los ntawm preexposure thiab postexposure theem siv ib tug GLM nrog ib tug tsawg-squares-sib cais mus kom ze (Mumford li al., 2012 ) nyob rau hauv qhov chaw ntawm txhua tus neeg koom. Txhua yam ntawm 16 yam khoom los ntawm cov txheej txheem scanned (piv txwv li, yim A yam khoom thiab yim C yam khoom los ntawm qhov zoo sib xws) tau ua qauv rov ua dua nyob rau hauv txhua qhov kev khiav ntawm lub sijhawm ua ntej thiab tom qab raug cais (Schlichting et al., 2015).

Cov khoom nthuav qhia tau ua qauv raws li qhov kev tshwm sim 1s, thiab tus regressor rau txhua yam khoom suav nrog tag nrho plaub qhov rov ua dua hauv kev ua haujlwm scanning. Txhua tus ntawm 16 cov khoom regressors tau convolved nrog lub canonical ob C HRF. Tom qab ntawd siv lub sijhawm lim dej. Cov GLMs suav nrog cov kev tsis sib haum xeeb ntxiv: cov lus tsa suab, lawv cov khoom siv hauv lub cev, kev hloov pauv hloov pauv, thiab DVARS (Power li al., 2012; Schlichting thiab Preston, 2014; Schlichting li al., 2015). Ntxiv cov lus tsa suab regressors tau ntxiv rau lub sij hawm cov ntsiab lus thaum lub taub hau txav tshaj ob qho tib si 0.5 hli rau lub moj khaum hloov chaw thiab 0.5 feem pua ​​​​ntawm kev hloov hauv BOLD teeb liab rau DVARS (Power et al., 2012). Cov duab Beta tau tsim rau txhua yam khoom A thiab C rau txhua qhov kev tawm tsam ua ntej thiab tom qab khiav, suav nrog 128 cov duab txheeb cais rau ib tus neeg koom.

Quantifying kev kawm txog kev hloov pauv hauv hippocampal subfield neural zoo sib xws. Cov qauv sib txawv thiab kev nco txog kev sib koom ua ke hauv hippocampus tau txheeb xyuas los ntawm kev txheeb xyuas qhov zoo sib xws (Kriegeskorte li al., 2008) siv hauv PyMVPA (Hanke et al., 2009). Kev tshawb nrhiav tau khiav sib cais nyob rau hauv anatomically anatomically txhais DG/CA2,3, CA1, thiab subiculum nyob rau hauv haiv neeg qhov chaw ntawm txhua tus neeg koom. Nyob rau hauv txhua qhov kev tshawb nrhiav lub ntsej muag (lub vojvoog=2 voxels, ntim=33 voxels) (Schapiro li al., 2012), zoo sib xws matrices tau tsim los ntawm kev suav cov pairwise Pearson qhov kev sib raug zoo rau 128 cov duab txheeb cais sib raug rau A thiab C cov khoom hauv preexposure thiab postexposure khiav, hloov mus rau Fisher's z. Tom qab ntawd, qhov kev hloov pauv ntawm cov qauv zoo sib xws vim kev kawm tau ntsuas los ntawm kev rho tawm qhov preexposure zoo sib xws qhov tseem ceeb los ntawm cov txiaj ntsig zoo sib xws hauv cov khoom sib xws.

Tom qab qhov kev hloov pauv hauv cov qauv zoo sib xws (tom qab no hu ua D) raug xam, D cov txiaj ntsig tau txheeb xyuas nyob ntawm seb tus nqi puas yog rau kev sib piv hauv triad lossis kev sib piv thoob plaws triad. Ob pawg ntawm qhov tseem ceeb no tau tso cai rau peb los txiav txim siab seb qhov kev hloov pauv tau cuam tshuam li cas los ntawm qhov xwm txheej sib tshooj vim kev kawm (hauv-triad sib piv txheej) txheeb ze rau cov hauv paus ntsiab lus uas yooj yim cuam tshuam qhov rov tshwm sim dua yam tsis muaj qhov tshwm sim sib tshooj (thoob-triad sib piv teeb). Qhov tseem ceeb, tsuas yog D qhov tseem ceeb uas muaj kev cuam tshuam thoob plaws kev sib raug zoo tau siv los txo qhov kev tsis ncaj ncees uas tuaj yeem qhia los ntawm autocorrelation hauv BOLD teeb liab (Mumford li al., 2012).

Txhawm rau soj ntsuam cov txiaj ntsig ntawm kev rov ua kom rov ua haujlwm thaum kawm txog kev hloov pauv hloov pauv, cov txiaj ntsig hauv triad D tau muab faib ntxiv raws li lub zog ntawm kev nco rov ua haujlwm thaum kawm ntawm cov khub sib tshooj. Rau txhua tus neeg koom, lub zog reactivation raug xam rau txhua qhov triad los ntawm kev siv qhov ntsuas qhov nruab nrab reactivation thoob plaws hauv lub network ntawm cov cheeb tsam uas tau txheeb xyuas hauv kev tshawb nrhiav lub teeb pom kev rov ua dua tshiab (saib daim duab 3A), nruab nrab ntawm cov kev tshawb fawb blocks. Triads tau muab faib ua qhov muaj zog reactivation triads thiab tsis muaj zog reactivation triads siv qhov nruab nrab ntawm qhov nruab nrab reactivation qhov tseem ceeb. Yog li, nyob rau hauv-triad D kev sib piv tau raug txheeb xyuas ntxiv rau hauv qhov muaj zog reactivation nyob rau hauv-triad D teeb thiab ib tug tsis muaj zog reactivation nyob rau hauv-triad D teem nyob rau hauv txhua txhua searchlight sphere. Thaum kawg, tag nrho cov teeb tsa D tau nruab nrab los tsim peb cov ntsiab lus tseem ceeb: qhov nruab nrab hauv-triad zoo sib xws hloov pauv rau qhov muaj zog reactivation triads (DWithin muaj zog), qhov nruab nrab hauv-triad zoo sib xws hloov pauv rau cov tsis muaj zog reactivation triads (DWithin weaker), thiab qhov nruab nrab hla-triad zoo sib xws hloov (hli). Peb piv cov ntsiab lus tseem ceeb no los txiav txim seb puas yog neural coding txawv raws li kev ua haujlwm ntawm lub zog reactivation.

Neural coding raug soj ntsuam siv plaub qhov sib txawv ntawm qhov sib txawv (Schlichting li al., 2015) (saib daim duab 4B). Ob qhov kev tshuaj ntsuam xyuas pom cov hippocampal voxels uas muaj kev nco txog kev sib koom ua ke lossis kev sib txawv thoob plaws txhua qhov triads, tsis hais txog lub zog reactivation. IntegrationOverall raug xam raws li (DWithin muaj zog - DAcross) 1 (DWithin weaker - DAcross), xav txog ntau dua nyob rau hauv-triad tshaj hla-triad zoo sib xws tom qab kawm thoob plaws txhua qib ntawm reactivation. DifferentiationOverall tau xam raws li (DAcross – DWithin muaj zog) 1 (DAcross – DWithin weaker), xav txog tsawg dua nyob rau hauv-triad tshaj hla-triad zoo sib xws thoob plaws txhua qib ntawm reactivation. Ob qhov kev tshuaj ntsuam ntxiv tau txheeb xyuas cov voxels uas neural coding varied raws li kev ua haujlwm ntawm lub zog reactivation (IntegrationReactivation thiab DifferentiationReactivation). Lub IntegrationReactivation searchlight tau txheeb xyuas cov voxels rau qhov kev sib koom ua ke tau tshwm sim rau ntau dua rau qhov muaj zog reactivation triads. IntegrationReactivation raug xam raws li (DWithin muaj zog - DWithin weaker). Hauv qhov sib piv, DifferentationReactivation searchlight tau txheeb xyuas cov voxels uas qhov sib txawv tau tshwm sim rau ntau dua rau qhov muaj zog reactivation triads. DifferentiationReactivation raug xam raws li (DWithin weaker – DWithin muaj zog).

Qhov tseem ceeb ntawm txhua qhov ntawm cov kev suav no tau txiav txim siab los ntawm kev sib piv cov txiaj ntsig zoo sib xws ntawm kev hloov pauv mus rau qhov tsis muaj kev faib tawm hauv txhua qhov kev tshawb nrhiav lub teeb. Qhov kev faib tawm null tau tsim ntau dua 1000 iterations los ntawm kev sib txuas ntawm cov hlwb thoob plaws DWithin muaj zog dua, DWithin tsis muaj zog, thiab DAcross teeb tsa thiab tom qab ntawd rov xam cov lej ntawm kev txaus siab rau txhua qhov kev rov ua dua. Qhov nruab nrab voxel ntawm txhua qhov kev tshawb nrhiav lub ntsej muag tau tshaj tawm qhov kev faib ua feem ntawm qhov tsis muaj kev faib tawm nrog qhov muaj txiaj ntsig ntau dua lossis sib npaug ntawm qhov pom zoo sib xws (piv txwv li, p-tus nqi). Cov pawg tseem ceeb tau raug txheeb xyuas siv tib txoj kev raws li cov kev tshawb nrhiav rov ua dua tshiab, tshwj tsis yog cov duab z-statistic tau warped mus rau qhov kev daws teeb meem hippocampal template es tsis yog cov qauv MNI resampled rau pawg-qib tsom xam. Cov ntawv qhia kev tshawb nrhiav teeb pom kev zoo li ntawd tau npog los ntawm txhua tus qauv hauv hippocampal subfield ua ntej kev kho pawg kom ntseeg tau tias pawg tsuas yog rau txhua qhov hippocampal subfield.

Post hoc soj ntsuam ntxiv soj ntsuam cov kev taw qhia ntawm kev sawv cev kev hloov pauv tau pom nyob rau hauv txhua qhov subfield txheeb xyuas los ntawm qhov kev tshawb nrhiav teeb pom kev zoo no. Ib qho kev ceeb toom tseem ceeb rau cov kev ntsuam xyuas tom qab no yog tias lawv tsis muaj kev ywj pheej kiag li vim tias lawv sib piv cov voxels preselected los nthuav tawm cov teebmeem tshwj xeeb raws li qhov sib txawv ntawm kev tshawb nrhiav. Yog li, peb cov kev soj ntsuam tom qab tsis ncaj qha piv rau DWithin qhov tseem ceeb rau cov khoom muaj zog thiab tsis muaj zog reactivation. Peb qhov kev soj ntsuam tom qab hoc es tsis txhob tsom mus rau qhov loj ntawm DAcross qhov tseem ceeb los ntsuas seb puas muaj kev hloov pauv thoob ntiaj teb hauv neural zoo sib xws thoob plaws lub sijhawm ua ntej thiab tom qab raug mob, ntxiv rau kev sib piv DWithin qhov tseem ceeb rau DAcross qhov tseem ceeb los ntsuas cov qib ntawm kev kawm txog kev sib koom ua ke thiab kev sib txawv.

Rau cov kev ntsuam xyuas tom qab no, kev hloov pauv zoo sib xws hauv DG/CA2,3, CA1, thiab subiculum tau suav rau txhua tus neeg koom nrog hauv thaj chaw ib txwm muaj. Cov kev tshawb nrhiav teeb pom kev pom los ntawm pab pawg tshawb nrhiav teeb pom kev tau hloov pauv mus rau hauv lub qhov ncauj qhov ntswg thiab rov qab-zoo li qub rau txhua tus neeg koom nrog qhov chaw uas siv cov kev hloov pauv tsis yog hauv ANTS. Rau txhua tus neeg tuaj koom, cov chaw nyob ib puag ncig tau nthuav dav nrog FSL siv lub thawv 3 * 3 * 3 hli ua cov ntsiav. Txhawm rau kom ntseeg tau tias pawg tseem txwv rau lawv qhov chaw subfield thaum hloov mus rau cov neeg koom nrog thaj chaw, txhua pawg tau npog qhov ncauj qhov ntswg siv lub qhov ncauj qhov ntswg subfield uas tau hais tseg rau txhua tus neeg koom. Ib tus neeg koom nrog CA1 pawg hauv ib cheeb tsam uas tsis muaj tus lej txaus rau kev txheeb xyuas qhov zoo sib xws (,10 voxels) thiab raug tshem tawm los ntawm kev tshuaj xyuas tom ntej ntawm lub subfield no. Rau cov neeg koom nrog ntxiv, peb suav qhov kev hloov pauv qhov nruab nrab zoo sib xws hauv txhua pawg sib cais rau triads cuam tshuam nrog kev rov ua kom muaj zog dua thaum kawm, cov uas cuam tshuam nrog qhov tsis muaj zog rov ua dua thaum kawm, thiab cov kab hauv qab triad.

Quantifying kev sib raug zoo ntawm neural ntsuas thiab tus cwj pwm. Kev sib raug zoo ntawm tus cwj pwm thiab peb cov kev ntsuas neural ntawm reactivation thiab sawv cev hloov pauv tau raug soj ntsuam siv tus qauv Linear Ballistic Accumulator (LBA) kom haum rau kev ua tau zoo ntawm qhov kev xeem inference (Morton li al., 2020). Rau txhua tus neeg koom nrog thiab subfield (CA1, DG / CA2,3, thiab subiculum), peb suav cov z qhab nia ntawm qhov kev hloov pauv zoo sib xws ntawm A thiab C los ntawm kev kawm mus rau kev kawm tom qab (D) rau txhua qhov triad. Peb kuj suav qhov z qhab nia ntawm A yam khoom reactivation hla triads rau txhua tus neeg koom. Peb mam li siv tus qauv LBA kom haum rau cov lus teb rau tus cwj pwm thiab lub sij hawm teb thaum lub sij hawm AC inference test, siv qhov zoo sib xws hloov thiab reactivation raws li kev kwv yees ntawm qhov sib txawv ntawm triads. Peb siv ntau theem Bayesian txoj hauv kev los kwv yees txhais tau tias txoj kab nqes nqes qhia txog kev sib raug zoo ntawm kev ntsuas neural thiab AC inference kev ua tau zoo. Qhov chaw zoo rau D ntsuas qhia qhov sib xws loj dua ntawm cov khoom A thiab C tom qab kev kawm tau cuam tshuam nrog kev xav tau nrawm dua thiab raug dua. Qhov chaw zoo rau kev ntsuas kev rov ua kom rov ua haujlwm qhia tau tias kev rov ua haujlwm ntau dua yog cuam tshuam nrog kev xav tau sai dua thiab raug dua.

Tus qauv txhais Tus qauv LBA (Brown thiab Heathcote, 2008) xav tias, ntawm txhua qhov kev sim, qhov pib taw tes k ntawm txhua lub accumulator yog kos los ntawm ib qho kev faib tawm ntawm lub sijhawm [0, A]. Txhua lub accumulator tom qab ntawd ua raws ib kab nrog txoj kab nqes ntawm d kom txog thaum nws mus txog qhov pib teb b. Ntawm txhua qhov kev sim, qhov sloped ntawm accumulator kuv yog kos los ntawm ib txwm faib nrog txhais tau tias vi thiab SD s (ntawm no, tsau ntawm 1). Lub sijhawm rau lub accumulator kom ncav cuag qhov pib yog (bk) / d. Peb tau ua qauv rau peb qhov kev xaiv yuam kev-xaiv qhov kev ntsuam xyuas siv peb lub accumulators nrog tus nqi qis v1 (rau cov lus teb raug) thiab v2 (rau ob qho lus teb). Raws li tau muab los ntawm cov lus piav qhia thawj zaug ntawm LBA qauv (Brown thiab Heathcote, 2008), qhov muaj peev xwm ceev ua haujlwm (PDF) rau accumulator I thaum lub sijhawm t yog raws li hauv qab no:

Qhov F thiab U yog qhov tshwm sim ceev ua kom muaj nuj nqi thiab cumulative faib cov haujlwm, ntsig txog tus qauv faib khoom. Qhov kev faib ua feem faib (CDF) rau accumulator I thaum lub sij hawm t yog raws li nram no:

PDF rau accumulator Kuv ntaus qhov pib ua ntej, thaum lub sij hawm t, yog qhov tshwm sim ntawm accumulator kuv ua tiav thaum lub sij hawm t, conditional rau lwm yam accumulators tsis tau tiav raws li nram no:

Vim hais tias drift tus nqi d yog kos los ntawm ib qho kev faib tawm, muaj qee qhov tshwm sim ntawm tsis muaj cov khoom ua tiav. Ua raws li kev ua haujlwm ua ntej (Brown thiab Heathcote, 2008; Annis li al., 2017), peb tau kho qhov tshwm sim ntawm qhov tshwm sim tsawg kawg yog ib qho accumulator muaj qhov zoo drift raws li hauv qab no:

Lub sijhawm tsis txiav txim siab (piv txwv li, lub sijhawm pom qhov kev sim stimuli) tau ua qauv raws li lub sijhawm ncua sijhawm t. Qhov tshwm sim ntawm qhov raug teb ntawm lub sijhawm t yog raws li hauv qab no:

Tus qauv tau ua tiav hauv Python 3.7 siv PsiReact 0.2 (Morton li al., 2020). Peb siv Bayesian sampling los kwv yees qhov tsis muaj, siv Tsis Muaj U-Turn Sampler (NUTS) siv hauv pyMC 3.9.2. Peb kho s=1 thiab b=8 los txhim kho qhov ruaj khov ntawm kev kwv yees. Ib qho kev cuam tshuam drift tus nqi parameter b 0, kuv rau cov lus teb raug raug kwv yees rau txhua tus neeg koom i. Peb kuj tau kwv yees tus nqi drift ntawm cov lus teb tsis raug v2, kuv rau txhua tus neeg koom. Peb siv cov neeg koom nrog z cov qhab nia ntawm qhov zoo sib xws hloov pauv rau txhua qhov subfield (xws li zCA1, ij) thiab kev kwv yees rov ua haujlwm (zReact, nws) los kwv yees tus nqi drift ntawm txhua qhov kev sim j. Kev sim-theem qhov sib txawv hauv qhov drift tus qauv tau ua qauv raws li kev sib xyaw ua ke ntawm kev hloov pauv zoo sib xws thiab rov ua dua z cov qhab nia. Qhov tseeb khoom drift tus nqi v1,ij rau cov neeg koom nrog kuv, sim j yog raws li hauv qab no:

Cov kev nqes hav (piv txwv li, b CA1, i) tau kwv yees rau txhua tus neeg koom nrog i. Txhawm rau txhim kho qhov ua tau zoo ntawm kev kwv yees rau tus kheej cov neeg koom tsis tau, peb txhais tau tias lawv tau kos los ntawm ib pab pawg-theem kev faib tawm. Cov kev faib ua ntej rau cov tsis muaj raws li hauv qab no:

Rau txhua qhov ntawm plaub txoj hlua, muaj qhov hloov kho theem ntawm 1000 iterations nrog lub hom phiaj lees txais ntawm 0.99, ua raws li 5000 qauv. Convergence tau soj ntsuam los ntawm kev siv cov qauv loj loj thiab qib-normalized faib cov peev txheej txo qis R^ (Vehtari li al., 2017). Peb ntsuas qhov haum ntawm tus qauv los ntawm kev suav cov ntsiab lus tom qab tsis zoo rau txhua qhov kev sim nrog rau simulating cov lus teb thiab lub sijhawm teb. Peb simulated 50 replications ntawm txhua qhov kev sim kom tau txais kev kwv yees zoo ntawm cov qauv kev ua tau zoo. Thaum kawg, peb suav 95 feem pua ​​​​ntawm cov high-density interval (HDI) rau txhua pab pawg-theem txhais tsis tau (xws li, mCA1 rau CA1) los txiav txim seb lawv txawv ntawm xoom, qhia txog kev sib raug zoo ntawm kev hloov pauv lossis rov ua dua thiab AC inference. kev ua tau zoo.

Cov txiaj ntsig

Kev coj cwj pwm Kev coj cwj pwm Thaum kawg ntawm theem pib ntawm khub (AB) kev kawm, cov neeg tuaj koom tau tsim muaj kev nco txog lub ntsej muag-zoo li ob lub ntsej muag thiab cov duab zoo nkauj. Txhua tus neeg tuaj koom tau dhau los ntawm qhov kev xeem zaum kawg (txhais tau tias qhov kev faib ua feem yog=0.91, SD=0 01) thiab tau muaj nyob rau hauv qhov kev tshuaj ntsuam tom ntej. Lub cim xeeb rau qhov sib tshooj (BC) cov khoom ua khub tau cuam tshuam los ntawm qhov pom qhov sib xws ntawm cov khoom sib txuas hla kev kawm ing (Fig. 2A, B). Ib qho kev rov ntsuas ANOVA nrog rau cov ntsiab lus nyob rau hauv cov ntsiab lus ntawm kev sib tshooj ntawm khub thaiv (1, 2, 3, 4) thiab qhov pom kev zoo sib xws (qhov tseeb match, siab zoo sib xws, qis zoo sib xws, tshiab) qhia tias qhov pom kev zoo sib xws modulated nco raug (cov nyhuv tseem ceeb ntawm thaiv, F(3,75)=79.93, p , 0.001, h2=0.762; thaiv kev sib cuam tshuam kev pom kev sib xws, F(9,225)=2.88, p=0.{{50}}03, h2=0.103 ) thiab lub sij hawm teb (qhov tseem ceeb ntawm qhov zoo sib xws ntawm qhov raug tri als, F(3,72) {{3{{1{105}}3}}}}.14, p=0.003, h{ {34}}.176). Rau thawj qhov kev kawm thaiv ntawm cov khub sib tshooj, kev ua tau zoo tshaj plaws (Daim duab 2A) thaum cov khoom sib txuas (B) yog qhov sib tw tiag tiag rau cov khub kawm pib (AB) txheeb ze rau txhua yam xwm txheej. Muaj qhov cuam tshuam ntawm qhov pom kev zoo sib xws hauv thawj qhov kev sim thaiv (qhov cuam tshuam ntawm qhov pom kev zoo sib xws hauv thawj qhov kev khiav, F(3,75)=6.901, p, 0.001, h2=0.216) tab sis tsis nyob rau hauv kev khiav tom ntej (F qhov tseem ceeb 0.479, tag nrho p 0.698, tag nrho h2 0.019). Hauv thawj qhov kev sib tw, post hoc paired t tests qhia tias qhov tseeb yog qhov siab tshaj plaws rau cov khub uas muaj qhov sib tw tiag tiag txheeb ze rau txhua tus khub (piv nrog qhov zoo sib xws: t(25)=3.33, p=0 .003, d=0.654; qis zoo sib xws: t(25)=4.52, p, 0.001, d=0.894; tshiab: t(25) {{67} }.74, p=0.011, d=0.539). Kev ua tau zoo dua rau cov khub zoo sib xws ntau dua cov khub uas tsis sib xws (t(25)=2.306, p=0.03, d=0.459). Tsis muaj qhov sib txawv ntawm qhov kev ua tau zoo ntawm qhov zoo sib xws thiab cov khub tshiab (t(25)=0.87, p=0.394, d=0.172) lossis qhov tsis zoo sib xws thiab tshiab khub (t(25)=0.76, p=0.452, d=0.151). Thaum sib tsoo hla thaiv, cov khub nrog qhov tseeb qhov sib tw muaj lub sij hawm teb ceev tshaj plaws (Fig. 2B) ntawm qhov tseeb p kev sim (piv nrog rau tag nrho lwm yam kev mob, t tus nqi 2.206, tag nrho, 0.05, tag nrho d 0.445). Lub sij hawm teb tsis txawv ntawm qhov zoo sib xws, qhov tsis zoo sib xws, lossis cov khub tshiab (tag nrho t tus nqi 1.748, tag nrho p. 0.05, tag nrho d 0.348)

Daim duab 2. Kev coj cwj pwm zoo. Ib khub Overlapping (BC) xeem raug thiab (B) lub sij hawm teb (tsuas yog kev sim) los ntawm kev kawm thaiv rau txhua qhov zoo sib xws. C, Hla-ib ntu (AC) qhov tseeb qhov tseeb thiab (D) lub sij hawm teb (tsuas yog kev sim) rau txhua qhov zoo sib xws. pp, 0.05 (paired t-tests). Qhov yuam kev bar qhia 6 SEM. Cov kab dotted qhia txog kev ua tau zoo ntawm 3- lwm txoj kev yuam kev xaiv.

Kev pom qhov zoo sib xws ntawm cov khoom sib txuas kuj cuam tshuam rau qhov sib txawv ntawm qhov tseeb (F(3,75)=26.61, p , 0.{19}}01, h{ {6}}.516). Cov neeg koom nrog yuav muaj feem cuam tshuam txog kev sib raug zoo ntawm cov ntsiab lus tsis raug cuam tshuam nrog kev nco (AC) thaum cov khoom sib txuas (B) yog qhov sib tw tiag tiag lossis zoo sib xws hauv cov khub sib tshooj (Fig. 2C). Inference kev ua tau zoo tsis txawv ntawm qhov tseeb match thiab siab zoo sib xws triads (t(25) {{10}}.20, p=0.24, d {{14} }.230), tab sis kev ua tau zoo rau kev sib tw tiag tiag triads zoo dua rau ob qho tib si qis triads (t(25)=6.82, p , 0.001, d=1.327) thiab triads tshiab (t( 25)=6.61, p , 0.001, d=1.286). Ib yam li ntawd, kev ua tau zoo rau qhov zoo sib xws triads tshaj qhov tsis zoo sib xws triads (t(25)=5.05, p , 0.001, d= 0.987) thiab triads tshiab (t(25)=5 .38, p, 0.001, d=1.055). Ua raws li kev ua tau zoo (Inference kev ua tau zoo tsis txawv ntawm qhov tsis zoo sib xws thiab cov triads tshiab (t(25)=1.17, p=0.254, d= 0.224). Txawm li cas los xij, performance rau qis zoo sib xws triads tau ntseeg tau zoo dua li lub caij nyoog (t(25)=2.22, p=0.04, d=0.435), qhov kev ua tau zoo rau kev tshaj tawm tshiab triad yog tsis (t(25)=0.47, p=0.64, d=0.093).

Kev txiav txim siab qhov kev txiav txim siab kuj tau nrawm dua rau qhov kev sib tw tiag tiag thiab cov xwm txheej zoo sib xws ntawm cov xwm txheej tshiab (F(3,72)=11.79, p , 0.001, h{ {6}}.329), nrog rau qhov kev sib tw rau qhov kev sib tw tiag tiag yog qhov nrawm tshaj plaws (Daim duab 2D). Lub sij hawm teb sai dua rau qhov sib tw tiag tiag triads txheeb ze rau qhov zoo sib xws (t(25) {{10}}.41, p=0.002, d=0.669) thiab tshiab triads (t(24)=5.00, p , 0.001, d=0.999), tab sis tsis txawv ntawm qhov zoo sib xws triads (t(25)= 1.64, p=0.114, d=0.321). Lub sij hawm teb tau nrawm dua rau qhov zoo sib xws triads piv nrog cov triads tshiab (t(24)=2.93, p=0.007, d=0.585), tab sis tsis txawv ntawm qhov qis zoo sib xws triads (t(25)=1.11, p=0.28, d=0.217). Tsawg zoo sib xws triads sai dua tshiab triads (t(24)=3.86, p=0.001, d=0.773). Ua ke, cov kev tshawb pom no qhia tau hais tias kev sib koom ua ke ntawm kev nco thiab kev sib cav sib ceg, ob qhov txheej txheem uas xav tias yuav txhawb nqa los ntawm hippo campal subfields (Schapiro et al., 2017), tau cuam tshuam los ntawm kev nkag siab zoo sib xws ntawm cov ntsiab lus sib koom, nrog rau kev ua tau zoo. nrog rau qib siab ntawm qhov sib txawv ntawm qhov sib txawv.

Reactivation ntawm overlapping nco thaum kawm

Txhawm rau kuaj seb cortical nco reactivation li cas thaum sib tshooj sib tshooj kev kawm cuam tshuam rau hippocampal subfield sawv cev, peb thawj zaug siv kev tshawb nrhiav teeb pom kev los txheeb xyuas qhov twg cov ntaub ntawv hais txog thawj khub tau rov ua haujlwm hauv cortex thaum kawm. Nyob rau hauv txhua qhov kev tshawb nrhiav lub teeb pom kev zoo, tus qauv cais tau raug cob qhia ntawm cov ntaub ntawv los ntawm ib qho chaw hauv cheeb tsam thiab tom qab ntawd siv rau qhov sib tshooj-ping khub kawm theem (Zeithamova li al, 2012), Lub teeb nrhiav pom thaj chaw uas cov pov thawj cais rau lub hom phiaj cate-gory ntawm cov khoom muaj feem cuam tshuam (lub ntsej muag lossis qhov chaw A cov khoom los ntawm thawj khub) tau dhau qhov kev ntsuas hauv qab ntawm cov ntaub ntawv pov thawj rau tib qeb muab los ntawm cov kev sim tshiab (lossis nonoverlapping). Peb pom cov pov thawj uas muaj feem xyuam nrog kev nco tau rov ua haujlwm dua thaum kawm cov khub sib tshooj hauv lub posterior cingulate cortex, occipital cortex, thiab parietal cortex (Fig. 3A).

Qhov tseem ceeb, tsis muaj qhov sib txawv ntawm lub zog reactivation raws li kev ua haujlwm ntawm A yam khoom (lub ntsej muag, scene) thoob plaws cheeb tsam identi fied hauv kev tshawb nrhiav teeb pom kev zoo (Daim duab 3B). Ib qho kev rov ntsuas ANOVA nrog rau cov ntsiab lus hauv cheeb tsam (sab laug parietal, txoj cai parietal, cingulate, superior occipital, inferior occipital) thiab stimulus qeb (lub ntsej muag, scene) qhia tau hais tias reactivation varied nyob rau hauv cov cheeb tsam (cov nyhuv tseem ceeb ntawm cheeb tsam, F ( 4,100)=2.84, p=0.028, h2=0.102) tab sis tsis txawv los ntawm pawg stimulus (qhov tseem ceeb ntawm qeb, F(1,25) {{13 }}.002, p=0.967, h2=0; qeb region inter action, F(4,100)=0.375, p=0.826, h{{ 24.015). Yog li, peb cov txiaj ntsig tsis tau tsav los ntawm ib qho kev txhawb nqa ib pawg thiab muaj kev cuam tshuam kev nco rov ua haujlwm dua li kev koom tes ntawm pawg tshwj xeeb proc essing cheeb tsam.

Peb tau sim ntxiv seb qhov kev pom zoo sib xws ntawm cov khoom B sib koom thoob plaws kev kawm cuam tshuam lub zog ntawm kev nco rov ua haujlwm rau cov khoom A. Peb kwv yees tias kev nco rov ua haujlwm thaum kawm yuav muaj zog dua rau cov khub txuas los ntawm cov khoom zoo sib xws. Siv ib txoj hauv kev zoo sib xws rau kev txheeb xyuas yav dhau los, kev tshawb nrhiav lub teeb pom kev sib cais tau txheeb xyuas thaj chaw uas cov ntaub ntawv pov thawj rau cov khoom muaj feem cuam tshuam A qhov ntau dua rau qhov kev sib tw tiag tiag dua li qhov siab thiab qhov tsis zoo sib xws. Raws li peb qhov kev xav, peb pom tias qhov zoo sib xws ntawm cov khoom sib xws tau hloov kho lub zog ntawm kev nco rov ua haujlwm ntawm sab laug parietal cortex thiab occipital cortex (Fig. 3C).

Nco reactivation cuam tshuam neural coding hauv hippocampal subfields

Txhawm rau kuaj peb qhov kev xav tias kev rov ua haujlwm ntawm qhov kev nco txog thaum lub sijhawm hloov pauv tshiab yuav ua rau cov neeg sawv cev tsis sib haum xeeb ntawm kev nco sib tshooj hauv DG / CA2,3 thiab CA1, peb suav cov hippocampal subfield coding raws li kev ua haujlwm ntawm lub cim xeeb reactivation lub zog thaum kawm. Ob leeg ua ntej thiab tom qab kawm cov khub, cov neeg koom tau raug tshuaj xyuas thaum saib cov duab ntawm cov khoom A thiab C los ntawm cov khub sib tshooj hauv qhov zoo sib xws (Fig. 1A). Peb ntsuas qhov sib txawv thiab kev sib koom ua ke los ntawm kev ntsuas kev kawm txog kev hloov pauv hauv cov qauv zoo sib xws rau cov khoom tsis ncaj ncees A thiab C los ntawm tib lub triad (Schlichting et al., 2015). Kev hloov pauv zoo sib xws hauv tib lub triad tau muab piv nrog lub hauv paus ntawm kev hloov pauv zoo sib xws ntawm cov khoom hauv cov triads sib txawv. Peb ntsuas qhov sib txawv los ntawm kev sim kom txo qis qhov sib xws ntawm cov khoom A thiab C tom qab kawm (Fig. 4A). Hauv qhov sib piv, kev sib koom ua ke yuav raug cim los ntawm cov qauv zoo sib xws ntawm cov khoom tsis ncaj ncees A thiab C, uas cuam tshuam txog kev tsim cov lej sib tshooj rau kev nco txog (Fig. 4A).

Txhawm rau ntsuas qhov cuam tshuam ntawm kev nco rov ua haujlwm thaum kawm ntawm neural coding ntawm cov ntsiab lus tsis raug cuam tshuam nrog kev nco, peb suav cov kev hloov pauv hloov pauv rau triads raws li lub zog ntawm reactivation hla kev sib tshooj kev kawm. Rau txhua tus neeg koom, peb txheeb cov khub sib tshooj rau hauv cov uas cuam tshuam nrog kev muaj zog thiab tsis muaj zog rov ua haujlwm ntawm cov khub thawj zaug, raws li kev sib faib nruab nrab ntawm qhov nruab nrab reactivation indices thoob plaws txhua pawg pom nyob rau hauv lub reactivation searchlight (Fig. 3A). Peb mam li muab piv rau neural coding ntawm indirectly hais txog A thiab C cov khoom txuam nrog ntau theem ntawm reactivation. Critically, tag nrho cov kev soj ntsuam ntsuam xyuas cov sawv cev hloov nyob rau hauv hippocampal subfields yog raws li cov ntaub ntawv los ntawm siab zoo sib xws triads xwb. Txoj hauv kev no tuav qhov pom kev zoo sib xws ntawm cov khoom sib txuas tas li, muab qhov kev ntsuam xyuas tseem ceeb ntawm seb puas nco reactivation mediates sawv cev hloov pauv saum toj no thiab dhau ntawm kev hloov pauv ntawm lub cev ib puag ncig.

Peb tau khiav plaub qhov kev tshuaj ntsuam xyuas nyob rau hauv ib tus neeg hippocampal subfields los ntsuam xyuas qhov cuam tshuam ntawm kev rov ua haujlwm ntawm kev kawm txog kev hloov pauv rau cov ntsiab lus ntawm kev nco tsis ncaj (Fig. 4B). Ua ntej, peb siv ob qhov kev tshuaj ntsuam xyuas los txheeb xyuas cov cheeb tsam hippocampal uas pom tias muaj kev sib txawv lossis kev sib koom ua ke ntawm A thiab C yam tsis hais txog qib ntawm kev nco rov ua haujlwm thaum sib tshooj kev kawm (DifferentiationOverall thiab IntegrationOverall, raws li) thiab pom tsis muaj kev cuam tshuam loj hauv hippocampus.

Daim duab 4. Kev ntsuam xyuas txog kev hloov pauv hloov pauv raws li kev ua haujlwm ntawm kev nco rov ua haujlwm thaum kawm. Kev kwv yees rau kev nco tsim los ntawm kev kawm sib koom. Ua ntej kev kawm, ib tus neeg A thiab C cov khoom nyob rau theem preexposure tsis qhia kev sib raug zoo. Tom qab kawm tiav, cov sawv cev ntawm cov khoom A thiab C tuaj yeem hloov pauv raws li kev ua haujlwm ntawm lawv cov kev sib raug zoo nrog cov khoom B. Peb tau sim rau ob qhov txiaj ntsig neural; Nyob rau hauv cov ntaub ntawv ntawm kev sib txawv, cov qauv neural rau indirect hais txog cov khoom A thiab C yog kwv yees kom tsawg dua nyob rau hauv lub postexposure theem piv rau cov kev sawv cev ntawm kev kawm. Nyob rau hauv sib piv, rau kev nco integration, neural zoo sib xws ntawm indirectly hais txog cov khoom A thiab C yog kwv yees kom nce los ntawm kev kawm mus rau tom qab kawm ntawv, xav txog qhov tsim ntawm overlapping neural codes txuas cov ntsiab lus nyob rau hauv cov xwm txheej. B, Plaub lub teeb pom kev sib txawv tau siv los txiav txim seb qhov cim xeeb sawv cev hauv hippocampal subfields sib txawv nrog lub cim xeeb rov ua kom lub zog thaum kawm. Ob lub teeb pom kev pom cov cheeb tsam uas sib txawv lossis kev sib koom ua ke tau tshwm sim thoob plaws txhua qib ntawm kev rov ua kom muaj zog. Lwm qhov teeb pom kev tshawb nrhiav pom thaj chaw uas neural coding sib txawv raws li kev ua haujlwm ntawm kev rov ua haujlwm. C, Kev kawm txog kev sawv cev hloov pauv hauv hippocampus. Cov cheeb tsam ntawm DG / CA2,3 thiab subiculum tau pom qhov sib txawv ntawm cov ntsiab lus tsis raug cuam tshuam ntawm kev nco, tab sis tsuas yog thaum rov ua kom muaj zog dua thaum kawm. Hauv qhov sib piv, ib cheeb tsam ntawm CA1 tau pom cov pov thawj ntawm kev nco kev sib koom ua ke, tab sis dua tsuas yog thaum rov ua kom muaj zog dua thaum sib tshooj kev kawm. Cov cheeb tsam Hippocampal tau piav qhia ntawm qhov qhib-qhov kev daws teeb meem siab pab pawg T2 qauv tsim rau hippocampal subfield txheeb xyuas (Schlichting li al., 2019). D, Neural zoo sib xws hloov pauv hauv pawg tau txheeb xyuas hauv kev tshawb nrhiav teeb pom kev zoo (C) tom qab rov qab normalization mus rau qhov chaw ib txwm muaj, lees paub qhov kev kwv yees ntawm cov txiaj ntsig tau los ntawm B. Inset, tib cov ntaub ntawv sib cais rau hauv-triad thiab hla-triad zoo sib xws ntsuas ua ntej xam cov qhab nees sib txawv. Vim tias qhov kev tshuaj ntsuam no yog raws li cov lus qhia hauv cov kev tshawb nrhiav teeb pom kev zoo, nws tsis yog kev ywj pheej tag nrho. Qhov yuam kev bar qhia 6 SEM.

Hloov chaw, peb tau kwv yees tias qhov kev sawv cev zoo sib xws ntawm cov khoom cuam tshuam ncaj qha hauv hippocampal subfields yuav nyob ntawm lub zog ntawm kev nco rov ua haujlwm thaum kawm ntawm cov khub sib tshooj. Txhawm rau ntsuas qhov kev xav no, peb tau khiav ob qhov kev tshawb fawb ntxiv uas tau saib rau kev sib cuam tshuam ntawm kev kawm txog kev hloov pauv thiab kev nco rov ua haujlwm; cov teeb pom kev sib cais hippocampal cov cheeb tsam uas qhia txog kev sib txawv lossis kev sib koom ua ke ntawm kev sim nrog kev rov ua kom muaj zog dua thaum sib tshooj kev kawm (DifferentiationReactivation thiab IntegrationReactivation).

Peb pom tias muaj zog rov ua dua tshiab ntawm thawj khub kev nco thaum kawm ntawm cov khub sib tshooj sib txawv ntawm qhov kev taw qhia ntawm kev hloov pauv tau pom hauv hippocampal subfields. Thaum pib (A) nco tau rov ua haujlwm dua thaum sib tshooj (BC) khub kev kawm, DG/CA2,3 tus qauv zoo sib xws tau txo qis ntawm cov khoom A thiab C los ntawm kev kawm mus rau kev kawm tom qab (Fig. 4C, D; DifferentiationReactivation). Subiculum nthuav tawm tib tus qauv zoo li DG / CA2,3, nrog kev rov ua kom muaj zog dua ua rau txo qis cov qauv zoo sib xws rau cov khoom A thiab C. Hauv qhov sib piv, CA1 tau pom qhov tsis sib haum xeeb ntawm kev sawv cev hloov pauv thaum lub cim xeeb rov ua kom muaj zog dua, nrog rau qhov zoo sib xws ntawm cov khoom A thiab C tom qab kawm (Fig. 4C, D; IntegrationReactivation). Cov kev tshawb pom no qhia tias kev sawv cev ntawm kev nco txog kev sib tshooj hauv hippocampal subfields muaj feem cuam tshuam rau kev nco rov ua haujlwm thaum kawm, nrog rau cov xwm txheej zoo ib yam ua rau cov lej sawv cev tsis sib xws hauv DG/CA2,3, CA1, thiab subiculum.

Thaum kawg, peb tau ua ntau qhov kev soj ntsuam tom qab hoc ntawm txhua qhov hippocampal subfield uas tau txheeb xyuas hauv kev tshawb nrhiav lub teeb kom nkag siab ntxiv tias yuav ua li cas reactivation modulated coding nyob rau hauv txhua cheeb tsam. Peb xub txheeb xyuas seb puas muaj kev hloov pauv thoob ntiaj teb hauv qhov sib xws ntawm neural tsuas yog ua haujlwm ntawm kev kawm los ntawm kev suav cov hla-triad D rau cov khoom tsis sib xws A thiab C (piv txwv li, hla-triad hauv paus). Hla-triad D tsis sib txawv ntawm xoom hauv CA1 (t(24)=0.383, p=0.705, d=0.077) lossis subiculum (t(25)=1.233, p=0.229, d=0.242), tab sis tau ntau dua xoom rau DG/CA2,3 (t(25)=3.431 , p=0.002, d=0.673). Cov txiaj ntsig no qhia tau hais tias qhov tseem ceeb ntawm kev sib piv qhov kev hloov pauv zoo sib xws rau cov xwm txheej cuam tshuam rau cov hauv paus ntsiab lus, txawm tias cov khoom tsis sib xws kuj tuaj yeem hloov qhov zoo sib xws tom qab kawm.

Tom ntej no, peb muab piv rau hauv-triad D rau triads txuam nrog muaj zog reactivation rau hla-triad D lub hauv paus raws li kev siv tau ntawm peb cov txiaj ntsig tshawb pom (Daim duab 4D). Raws li tau hais dhau los, qhov kev ceeb toom rau qhov kev tshuaj xyuas no yog tias cov txiaj ntsig tau muaj feem cuam tshuam los ntawm kev xaiv cov voxels txheeb xyuas hauv cov neural coding searchlight tsom xam. Raws li cov qauv kev kwv yees ntawm qhov sib txawv ntawm qhov sib txawv (Fig. 4B), peb pom cov pov thawj rau kev sib txawv, uas qhov kev hloov pauv ntawm neural zoo sib xws rau triads cuam tshuam nrog kev muaj zog reactivation tsawg dua li qhov hla-triad hauv paus hauv DG/ CA2,3 (t(25))=2.298, p=0.030, d=0.451) thiab subiculum (t(25)=3.158, p=0.004, d=0.619). Hauv CA1, peb tau qhia txog kev sib koom ua ke nrog ntau dua qhov zoo sib xws hauv triads cuam tshuam nrog kev rov ua kom muaj zog dua tom qab kawm txheeb ze rau cov kab hauv qab triad (t(24)=1.766, p=0.090, d=0.353). Ua ke, cov kev txheeb xyuas tom qab no txhawb nqa qhov txiaj ntsig ntawm kev tshawb nrhiav teeb pom kev zoo thiab qhia tau tias qhov kev sawv cev ntawm cov xwm txheej sib tshooj hauv subfields cuam tshuam los ntawm kev rov ua dua ntawm kev nco txog thaum kawm.

Raws li kev tshawb nrhiav kev tshawb fawb, peb kuj tau txheeb xyuas hauv-triad D rau triads cuam tshuam nrog kev tsis muaj zog rov ua dua thaum kawm. Peb pom cov pov thawj rau kev koom ua ke hauv DG/CA2,3 (t(25)=3.709, p=0.001, d=0.727) thiab ib qho kev sib txawv hauv subiculum (t( 25). Qhov txiaj ntsig no qhia tau tias kev hloov pauv hauv DG / CA2,3 tuaj yeem sib txawv raws li kev ua haujlwm ntawm qib kev sib tw, uas yuav txawv thaum lub cim xeeb muaj zog lossis tsis muaj zog rov ua haujlwm. Tsis muaj qhov sib txawv ntawm cov kab hauv qab tau pom rau triads cuam tshuam nrog kev rov ua haujlwm tsis muaj zog hauv CA1 (t(24)=1.062, p=0.299, d=0.212).

Kev sib koom ua ke ntawm kev nco txhawb kev txiav txim siab peb siv tus qauv Bayesian multilevel los tshuaj xyuas kev sib raug zoo ntawm kev hloov pauv zoo sib xws tom qab kawm (piv txwv li, kev sib koom ua ke lossis kev sib txawv) thiab kev ua tau zoo ntawm AC inference test. Peb kuj tau tshuaj xyuas kev sib raug zoo ntawm kev rov ua kom muaj kev nco txog thaum kawm thiab kev ua tau zoo. Ib tus neeg koom nrog raug tshem tawm los ntawm qhov kev tshuaj ntsuam no vim tias tsis txaus ntawm voxels hauv CA1 (,10 voxels). Peb siv tus qauv LBA ib txhij ua qauv kev txiav txim siab qhov tseeb thiab lub sijhawm teb. Peb siv Bayesian sampling nrog tus qauv los kwv yees qhov nqes hav ntawm kev sib raug zoo ntawm inference kev ua tau zoo thiab triad-theem variability nyob rau hauv zoo sib xws hloov thiab nco reactivation. Peb thawj zaug soj ntsuam seb qhov piv txwv Bayesian tau sib koom ua ke. Tsis muaj qhov sib txawv thaum kuaj; rau txhua qhov parameter hauv tus qauv, [Rhat] yog, 1.00102 thiab cov qauv ua tau zoo yog tsawg kawg yog 5225. Cov txiaj ntsig no qhia tau tias cov qauv sib txuas ua tiav, thiab muaj cov qauv txaus los kwv yees txhua qhov ntsuas.

Peb siv cov ntsiab lus tom qab tsis zoo los simulate cov qauv lus teb thiab pom tias muaj qhov zoo haum rau kev soj ntsuam ac curacy (Fig. 5A) thiab lub sij hawm teb (Fig. 5B) ntawm qhov kev xeem inference, nrog rau kev zam ntawm cov kev sim me me nrog lub sij hawm teb ntev heev. Qhov nruab nrab txoj kab nqes rau kev hloov pauv ntawm kev kawm (Daim duab 5C) tau zoo rau cov subiculum (95 feem pua ​​HDI=[0.043, 0.477], d {{10}}.37) thiab nco reactivation (HDI=[{21}} 0{{30}}5, {{ 43}}.437], d=1.51). Txoj kab nqes nqes rau CA1 (HDI {{20}}} [ 0.189, 0.244], d=0.15) thiab DG/CA2,3 (HDI=[ 0.393, 0.102], d=0.50) tsis txawv ntawm xoom . 95 feem pua ​​​​HDIs rau lwm cov qauv tsis muaj raws li hauv qab no: A=[2.059, 5.601], t=[{{7{{ 72}}}} . , s CA1=[0.004, 0.458], s DG/CA2,3=[0.010, 0.577], sSubiculum=[0.002, 0.408], and sReact=[ 0.0002, 0.327]. Cov txiaj ntsig no qhia tau hais tias ntau dua kev nco reacti vation thaum kawm thiab ntau dua AC zoo sib xws tom qab kawm hauv subiculum kwv yees sai dua thiab muaj tseeb dua inference nyob rau theem ntawm ib tus neeg sim.

TSEEM CEEB CISTANCHE: Txhim kho nco

Kev sib tham

Peb cov txiaj ntsig tau qhia tias cov kev nco rov ua haujlwm tau qhia txog kev sawv cev ntawm cov xwm txheej muaj feem cuam tshuam li cas hauv hippocampal circuit. Reactivation ntawm yav dhau los nco thaum lub sij hawm encoding ntawm tshiab, overlapping txheej xwm kwv yees nyob rau hauv-ntu inference kev ua tau zoo thiab muaj qhov sib txawv rau cov sawv cev hauv hippocampal subfields; muaj zog reactivation coj mus rau qhov sib txawv ntawm overlapping nco nyob rau hauv DG / CA2,3 thiab subiculum, thaum ib txhij txhawb kev koom ua ke ntawm cov tib nco nyob rau hauv CA1. Kev ua haujlwm ua ntej tau tsom mus rau kev piav qhia hippocampal subfield coding nyob rau hauv cov nqe lus ntawm kev hloov pauv kev ua haujlwm los ntawm kev hloov pauv hauv ib puag ncig cues ua rau muaj qhov sib txawv neural output (Leutgeb li al., 2004, 2007; Lacy et al., 2011; Yassa and Stark, 2011). Ntawm no, peb qhia tau hais tias kev hloov pauv hauv kev nkag siab ntawm kev nkag siab tsis yog tib qho kev txiav txim siab sawv cev kev kawm hauv hippocampal subfields. Hloov chaw, peb cov ntaub ntawv qhia tias hippocampal subfield coding yog txuas ntxiv los ntawm qib uas qhov kev paub tshiab ua rau rov ua haujlwm ntawm cov ntu cuam tshuam. Peb cov txiaj ntsig yog li txuas ntxiv qhov kev tshawb pom ua ntej los qhia, ntawm qib sawv cev, tias cortical nco reactivation drives dissociations nyob rau hauv hippocampal subfield coding nyob rau hauv lub ntsej muag ntawm kev sib tw ntawm heev zoo li nco.

Kev ua haujlwm ua ntej ntawm hippocampal tus sawv cev tau tsim cov ntsiab lus ntawm subfield coding raws li cov txheej txheem tsis siv neeg hauv kev teb rau ib puag ncig kev hloov pauv, nyob rau hauv qhov kev nkag siab xav tau suav tias yog tus tsav tsheb tseem ceeb ntawm cov lus teb hippocampal. Piv txwv li, cov kev tshawb fawb electrophysiological thaum ntxov hauv nas ntsuas yuav ua li cas tso cov lus teb hauv hippocampal subfields remapped li tsiaj navigated ib puag ncig nrog maj mam hloov perceptual nta (Guzowski li al., 2004; Lee et al., 2004; Leutgeb et al., 20074, 2007, 2004. ; Vazdarjanova thiab Guzowski, 2004). Cov hauj lwm zoo li no tau qhia tias kev hloov pauv me me hauv ib puag ncig cov yam ntxwv ua rau muaj kev hloov pauv loj hauv DG thiab CA3 cov lus teb, xav txog kev hloov pauv ntawm cov qauv tswv yim. Piv txwv li, CA1 cov lus teb tau hloov maj mam, scaling linearly nrog tus nqi ntawm perceptual hloov ntawm ib puag ncig; rau ib puag ncig uas zoo sib xws, CA1 kev ua tau pom muaj kev sib tshooj ntau dua hauv kev teb. Kev ua haujlwm ua ntej ntawm tib neeg tau siv txoj hauv kev zoo sib xws, nthuav qhia cov neeg koom nrog cov duab zoo sib xws (piv txwv li, cov duab ntawm ob lub txiv apples sib txawv) thiab ntsuas qhov loj ntawm hippocampal subfield teb rau ob daim duab (Bakker li al., 2008; Lacy li al. , 2011). Hauv cov kev tshawb fawb no, DG / CA2,3 tau qhia cov lus teb tshiab rau ob qho tib si cov duab zoo sib xws, tawm tswv yim cais coding ntawm ob daim duab. CA1 thiab subiculum cov lus teb rau qhov thib ob, cov duab zoo sib xws los ntawm ib khub, txawm li cas los xij, raug txwv tsis pub cuam tshuam nrog kev nthuav qhia ntawm thawj khub tus tswv cuab, tawm tswv yim zoo sib xws ntawm cov duab ua ke.

Thaum yav dhau los tsiaj thiab tib neeg kev ua haujlwm tau nthuav tawm qhov tseem ceeb ntawm kev ua haujlwm ntawm hippocampal subfield, peb qhov kev tshawb pom tau tsim los ntawm kev ua haujlwm los qhia tias hippocampal sawv cev kev kawm tsis yog ib qho kev ua haujlwm nkaus xwb tab sis hloov tau cuam tshuam los ntawm kev nco rov ua haujlwm (Hulbert and Norman, 2015; Kim et al., 2017; Ritvo et al., 2019). Peb pom tias hippocampal subfield dissociations yog qhov pom tseeb tshaj plaws thaum yav dhau los nco tau rov ua haujlwm zoo, ua kom muaj kev sib tw kev kawm uas txhawb kev sib txawv hauv DG / CA2,3 thiab subiculum, ib txhij nrog kev koom ua ke hauv CA1. Peb cov ntaub ntawv yog li qhia qhov yuav tsum tau ua kom muaj nuj nqis ntawm ob qho tib si kev nkag siab zoo sib xws ntawm cov xwm txheej thiab yuav ua li cas overlapping perceptual nta ua rau nco reactivation kom tag nrho cov account rau yuav ua li cas dissociable sawv cev tshwm sim nyob rau hauv lub hippocampal circuit. Ib qho kev nthuav dav ntawm kev ua haujlwm ntawm tib neeg ua ntej tau piav qhia saum toj no yog qhov kev sib cais ntawm cov chaw ua haujlwm nyob ntawm qhov kev ua haujlwm tau ua (Kirwan thiab Stark, 2007; Bakker et al., 2008; Lacy et al., 2011). Thaum qhov kev sim ua haujlwm tseem ceeb (piv txwv li, qhov pom kev zoo sib xws ntawm cov khoom) yog qhov xwm txheej rau cov neeg koom tes ua haujlwm, kev sib cais ntawm subfields tau pom (Bakker li al., 2008; Lacy li al., 2011). Txawm li cas los xij, thaum tib txoj kev stimuli thiab kev nthuav qhia tau ua ke nrog kev ua haujlwm siab, kev sib cais tsis tshua pom tseeb (Kirwan thiab Stark, 2007). Mechanistic qhov chaw ntawm cov kev tshawb pom sib txawv no tseem tsis tau nthuav tawm. Los ntawm kev txheeb xyuas lub cim xeeb rov ua haujlwm thaum lub sijhawm ua haujlwm nrog lub hom phiaj los yog qhov xwm txheej, kev nkag siab ntxiv yuav tau txais txog yuav ua li cas cov hom phiaj ua haujlwm cuam tshuam rau qhov kev sib tw ntawm kev nco cuam tshuam li cas rau cov neeg sawv cev neural (Richter et al., 2016).

Peb qhov kev tshawb pom tej zaum yuav yog lub tswv yim ntawm kev saib xyuas thiab tsis saib xyuas cov qauv ntawm kev kawm, uas txhua tus tsom mus rau cov hom phiaj kev kawm sib txawv. Txawm hais tias kev saib xyuas kev kawm yog qhia los ntawm kev sib piv cov sawv cev rau kev hnov ​​​​lus pom ncaj qha hauv ib puag ncig, kev kawm tsis muaj kev saib xyuas kho cov sawv cev kom txo qis kev sib tw ntawm qhov kev paub tam sim no thiab rov ua kom lub cim xeeb rov ua dua los ntawm qhov kev tshwm sim tshiab (Ritvo li al., 2019) los ntawm kev sib koom ua ke lossis kev sib txawv. Txawm hais tias kev kawm yuav cuam tshuam txog qhov sib npaug ntawm kev saib xyuas thiab tsis saib xyuas cov txheej txheem, peb qhov kev tshawb pom qhia tias cov kev nco rov qab ua haujlwm yog qhov tseem ceeb ntawm cov tswv yim coding dissociable tshwm sim thoob plaws hippocampal subfields.

Txog niaj hnub no, tsuas yog ib qho kev tshawb fawb hauv tib neeg tau siv ntau qhov kev txheeb xyuas sawv cev los txheeb xyuas qhov sib txawv ntawm hippocampal subfields, tshwj xeeb tshaj yog thaum tib neeg tau txais cov ntaub ntawv hais txog kev sib koom lossis cov ntsiab lus sib txawv (Dimsdale-Zucker li al., 2018). Txoj kev tshawb no qhia tau hais tias cov khoom kawm nyob rau hauv tib lub ntsiab lus spatial elicited overlapping activation qauv nyob rau hauv CA1 thiab txawv qauv nyob rau hauv DG / CA2,3 thaum retrieval txheeb ze rau cov khoom uas tsis qhia contextual ntaub ntawv. Cov kev tshawb pom tam sim no txawv ntawm qhov kev tshawb fawb no hauv ntau txoj hauv kev tseem ceeb. Ua ntej, txoj kev tshawb fawb ua ntej ntsuas cov lej subfield thaum lub sijhawm nco tau rov qab, thaum peb txoj haujlwm qhia txog cov txheej txheem kev kawm uas ua rau muaj kev cuam tshuam ntawm subfield sawv cev. Tshwj xeeb tshaj yog, qhov kev kawm ua ntej tsis tau txheeb xyuas qhov rov ua haujlwm ntawm qhov kev nco zoo li cas, txawm tias thaum kawm lossis rov qab los, ntsig txog hippocampal subfield coding. Ntawm no, peb qhia txog kev tsis sib haum xeeb hauv hippocampal subfield coding raws li kev nco rov ua haujlwm. Tsis tas li ntawd, peb qhia tau hais tias neural codes tsim los ntawm hippocampal subregions tsis tsuas yog txhawb kev paub yooj yim (Dimsdale-Zucker li al., 2018) lossis spatial nco (Leutgeb li al., 2004, 2007), tab sis kuj suav nrog kev sib raug zoo ntawm kev nco (see. Schlichting et al., 2014). Kev txiav txim siab ntawm kev txiav txim siab tau nrawm dua thiab muaj tseeb dua nrog nce qhov zoo sib xws ntawm cov khoom tsis ncaj tom qab kawm hauv subiculum, qhia tias cov lej sib tshooj txhawb nqa kev paub dhau los ntawm kev paub ncaj qha.

Peb pom tias subiculum sawv cev taug qab kev txiav txim siab yuav cuam tshuam tias subiculum yog cov qauv tsim tawm ntawm hippocampal circuit (O'Mara li al., 2001), uas ua lub luag haujlwm tseem ceeb hauv kev nco qab (Viskontas et al., 2009; Lindberg et al. , 2017). Thaum lub subiculum tau pom cov pov thawj ntawm kev kawm txog kev sib txawv rau cov khub sib tshooj tag nrho, peb cov ntaub ntawv ua qauv qhia tau hais tias kev hloov pauv hauv subiculum qhia txog cov lus teb txuas ntxiv mus. Kev sib xyaw ua ke ntau ntxiv (uas tuaj yeem xav tias qhov sib txawv tsawg dua) txhawb kev xav tau nrawm dua thiab muaj tseeb dua. Peb cov txiaj ntsig tau qhia tias, thaum nco tau ntau dua (lossis tsawg dua sib txawv), qhov kev xav tau yooj yim los ntawm kev khaws cov khoom sib txuas ntawm cov khoom tsis ncaj (Shohamy thiab Wagner, 2008; Schlichting et al., 2014); Hauv qhov sib piv, qhov sib txawv yuav ua rau qeeb qhov kev xav ntawm ob qhov sib txawv uas yuav tsum tau muab rov qab thiab rov ua dua ntawm qhov kev sim (Koster li al., 2018).

Zoo li subiculum, DG / CA2,3 nthuav tawm kev kawm txog kev sib txawv ntawm cov ntsiab lus tsis raug cuam tshuam nrog kev nco thaum nco rov ua kom muaj zog dua thaum lub sij hawm encoding. Txawm li cas los xij, nws yuav tsum raug sau tseg tias DG / CA2,3 qhov sib txawv ntawm qhov sib tshooj ntawm lub cim xeeb tsuas yog pom muaj feem cuam tshuam nrog qhov tsis sib xws, hla-triad hauv paus; tsis muaj kev hloov pauv ntawm qhov zoo sib xws los ntawm kev kawm mus rau kev kawm tom qab kawm rau cov khoom tsis ncaj qha ntawm lawv tus kheej (Fig. 4D, inset). Qhov kev tshawb pom no zoo ib yam nrog kev ua haujlwm ua ntej uas qhia txog kev sib txawv ntawm hippocampal rau cov txheeb ze ntawm cov xwm txheej tsis sib xws tom qab kawm (Favila li al., 2016; Dimsdale-Zucker li al., 2018), thaum tseem tswj hwm cov kev hloov pauv hauv qhov zoo sib xws uas tshwm sim dhau sijhawm. Ntxiv mus, DG / CA2,3 tau pom cov pov thawj rau kev nco kev sib koom ua ke thaum lub cim xeeb rov ua haujlwm tsis muaj zog thaum kawm, qhia txog qhov muaj peev xwm rau ntau tus sawv cev muaj zog hauv cheeb tsam no. Piv txwv li, kev sib tw nco uas tau txais los ntawm kev rov ua dua tuaj yeem muaj kev sib raug zoo tsis yog kev sawv cev rau kev hloov pauv hauv DG/CA2,3 (Ritvo li al., 2019). Kev rov ua kom muaj zog dua tuaj yeem txhawb kev sib txawv; tsis muaj zog lossis nruab nrab theem ntawm reactivation tuaj yeem ua rau kev sib koom ua ke, thiab tsis muaj qhov rov ua dua tuaj yeem tsim cov sawv cev tsis sib tshooj uas sib cais los ntawm passive orthogonalization. Lub tswv yim coding nyuaj no tuaj yeem piav qhia vim li cas DG / CA2,3 qhia cov pov thawj ntawm kev sib txawv (Kim li al., 2017) thiab kev sib koom ua ke (Schapiro et al., 2012) sawv cev nyob rau hauv ntau qhov xwm txheej. Xwb, peb cov txiaj ntsig tuaj yeem cuam tshuam txog kev siv thaj tsam DG / CA2,3 ua ke, cov khoom siv uas xav tias yuav nthuav tawm cov haujlwm sib txawv ntawm ib puag ncig cues thiab ua rau lub cim xeeb sawv cev (Yassa thiab Stark, 2011). Cov qauv kev soj ntsuam ntawm cov txiaj ntsig qhia tau hais tias kev txheeb xyuas lub cim xeeb rov ua haujlwm nrog rau kev hloov pauv tus sawv cev yog qhov tsim nyog kom nkag siab meej tias kev sib tw nco cuam tshuam li cas rau kev sawv cev ntawm kev kawm hauv DG / CA2,3.

Hauv kev xaus, peb qhov kev tshawb pom pom tau txhawb nqa cov qauv kev suav tsis ntev los no ntawm hippocampal circuit (Schapiro li al., 2017); Kev simulation los ntawm tus qauv no qhia tias CA1 tuaj yeem sawv cev rau kev sib raug zoo thoob plaws cov xwm txheej, thaum DG thiab CA3 cov sawv cev yuav hais txog qhov sib txawv ntawm cov ntu zoo sib xws. Peb qhov kev tshawb pom tau ua raws li cov kev kwv yees kwv yees no, nrog CA1 tsim kev sib koom ua ke sawv cev rau kev nco zoo sib xws, thaum DG/CA2,3 thiab subiculum sib txawv cov kev paub tib yam. Tsis tas li ntawd, peb qhia tau hais tias hippocampal cov sawv cev txhawb nqa cov kev xav tshiab, ua kom yooj yim rau kev tshawb pom ntawm kev sib raug zoo ntawm kev sib txawv tab sis muaj feem cuam tshuam. Cov hauj lwm tam sim no qhia ntxiv tias hippocampal subfield dissociations tsis yog ib qho yooj yim ua haujlwm ntawm kev nkag siab, tab sis tshwm sim los ntawm kev sib tw hauv kev nco thaum kawm. Ua ke, txoj kev tshawb fawb tam sim no ua rau peb nkag siab txog qhov kev paub ua ntej ua li cas cov xwm txheej tshiab tau sawv cev nyob rau hauv hippocampal circuit, muab qhov kev sim ua pov thawj ntawm cov kev kwv yees tseem ceeb ntawm cov qauv kev suav ntawm hippocampal nco ua haujlwm.

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