Izifundo ezikhokelwa ngumvuzo ngaphandle kwe-dopamine kwi-nucleus accumbens: imisebenzi yokudibanisa ye-cortico-basal ganglia network (2008)

Sekuyinto eqhelekileyo kuncwadi lwamva nje ukufumana ingqikelelo ye-monolithic 'yomvuzo' esetyenziswa ngokufanayo ekuziphatheni okunqwenelayo, nokuba ichaza nantoni na elungileyo kumzimba (idla ngokusuka kumbono womvavanyi), okanye isetyenziswe ngokutshintshanayo namagama amadala afana nala. 'ukuqinisa' okanye 'inkuthazo.' Le meko yemicimbi iyakhuthazwa, ukuba ayisiyiyo ngokwayo isiphumo, kugxilwe kwi-neural substrate enye 'yomvuzo' obandakanya ukukhutshwa kwe-dopamine (DA) kwi-nucleus accumbens.I-Berke kunye neHyman, 2000; UGrace et al., 2007).

Ikhonkco phakathi kwendlela ye-mesoaccumbens kunye nomvuzo, evunyiweyo kumashumi eminyaka eyadlulayo, iye yavuselelwa bubungqina bamva nje bokuba isiginali ye-phasic ye-DA ifaka impazamo yokuxela kwangaphambili umvuzo, ekusenokwenzeka ukuba isebenza njengophawu lokufundisa kwi-associative learnin.g (Schultz et al., 1997). Ngokweyona ngcaciso idumileyo, kanye njengokuba kukho umqondiso omnye womvuzo, ngoko kukho umqondiso omnye wokufunda okukhokelwa ngumvuzo, oku kuthetha unxulumano phakathi kovuselelo kunye nomvuzo (UMontague et al., 2004). Umbuzo wokuba olu hlobo lokufunda luyilawula njani indlela yokuziphatha eguquguqukayo, nakuba kunjalo, uye watyeshelwa; kucingelwa nje ukuba isiginali ye-dopamine yanele kokubini ukufunda kwangaphambili, kunye neempendulo ezinemiqathango eziveliswa ngoko, kunye nezenzo ezijolise kwiinjongo ezikhokelwa lumanyano lwabo nomvuzo. Ngenxa yoko, ugqaliselo lolona phando luninzi kwicandelo lomvuzo kunye nokulutha kukubonakaliswa kwe-DA kunye neplastiki ehambelanayo kwindlela ye-mesoaccumbens (EBerridge noRobinson, i-1998; Hyman et al., 2006; UGrace et al., 2007).

Lo mbono wenkqubo yomvuzo, njengoko uqondwa ngakumbi (IKhadidi kunye no-., 2002; I-Balleine, 2005; Everitt kunye noRobbins, i-2005; Hyman et al., 2006), akonelanga kwaye uyalahlekisa. Ayonelanga kuba akukho kuzuza okanye ukusebenza kwezenzo ezijoliswe kwiinjongo ezinokuchazwa ngokweenkqubo zonxulumano ezilamla ukufunda okuvuzwayo.. Kuyalahlekisa, ngaphezu koko, ngenxa yokuba ugxininiso olulodwa kumsebenzi wendlela ye-mesoaccumbens, engeyomfuneko okanye eyaneleyo kwizenzo ezijoliswe kwiinjongo, iphambukile ingqalelo kumbuzo obaluleke kakhulu wokuba zeziphi izenzo ezijoliswe kwiinjongo kunye nendlela eziphunyezwa ngayo. ngengqondo. Ewe, ngokobungqina obuguqukayo obuvela kwiindlela ezahlukeneyo zovavanyo, into ebikhe yabonakala ngathi yindlela enye yomvuzo inokubandakanya iinkqubo ezininzi ezineziphumo ezahlukeneyo zokuziphatha kunye ne-neural substrates.Corbit et al., 2001; ODoherty et al., 2004; Yin et al., 2004; Delgado et al., 2005; Yin et al., 2005b; IHaruno kunye neKawato, ngo-2006a; UTobler et al., 2006; Jedynak et al., 2007; URobinson et al., 2007; UTobler et al., 2007).

Apha sizama ukuveza ezinye zeengxaki ezinxulumene nemodeli yangoku ye-mesoaccumbens kunye nokuphakamisa, endaweni yayo, imodeli eyahlukileyo yokufunda okukhokelwa ngumvuzo. Siyakuxoxa ukuba i-striatum sisakhiwo esine-heterogeneous ephezulu enokuthi yahlulwe ibe yimimandla emine esebenzayo, nganye kuzo isebenza njenge-hub kuthungelwano olusebenzayo oluhlukileyo kunye nezinye izinto ze-cortical, thalamic, pallidal, kunye ne-midbrain.. Imisebenzi edibeneyo yolu thungelwano, ukusuka kwimveliso yeempendulo ezingenamiqathango ezifunwa ngumvuzo wokulawula izenzo ezijoliswe kwiinjongo, zinokwahlulwa kwaye zifundwe kusetyenziswa iimvavanyo zokuziphatha zangoku.

Uqikelelo kunye nolawulo

Indlela ye-mesoaccumbens ihlala icingelwa ukuba iyimfuneko ukuze kufunyanwe umanyano phakathi komvuzo kunye novuselelo lwendalo oluqikelela loo mvuzo. Ngokomzekelo, kwezinye iimvavanyo ezivavanya umsebenzi we-phasic weeseli ze-DA ezifunyanwe ngumvuzo, iinkawu zaqeqeshelwa ukudibanisa i-stimulus kunye nokuhanjiswa kwejusi (I-Waelti et al., 2001) kwaye emva koko uphendule kwi-stimulus ngempendulo enemiqathango (CR) -i-licking elindelekileyo. Ukukhothwa kwenkawu kunokujoliswa kumgomo, kuba ikholelwa ukuba kuyimfuneko ukufumana ijusi. Ngenye indlela, ukukhothwa kunokuphakanyiswa yi-antecedent stimulus apho ijusi idibene nayo. Yeyiphi kwezi zigqibo zokukhothwa kweenkawu ezilawula ukuziphatha kuyo nayiphi na imeko ayaziwa kuqala, kwaye ayinakuqinisekiswa ngokuqwalasela okungaphezulu; inokumiselwa kuphela ngokusebenzisa iimvavanyo ezenzelwe ngokukodwa le njongo. Ezi mvavanyo, ezithathe amashumi eminyaka ukuba ziphuhle, zenza undoqo wenkqubela phambili enkulu yanamhlanje kufundo lokufunda nokuziphatha (1 Table). Ukususela ekusetyenzisweni kwezi mvavanyo, eziza kuxutyushwa ngezantsi, ngoku siyazi ukuba impendulo efanayo yokuziphatha - nokuba yindlela ye-ambulatory, i-orienting, okanye icinezela i-lever-inokuthi ivele kwiimpembelelo ezininzi ezingenakulinganiswa.

  

1 Table

Ukufunda okukhokelwa ngumvuzo

Ukungabi naluvelwano kumbindi ophakathi kwezona zigqibo zokuziphatha yeyona ngxaki iphambili kuhlalutyo lwangoku lwe-neuroscientific yokufunda okukhokelwa ngumvuzo. To ukuqonda ukubaluleka kwale ngxaki, kuyimfuneko ukuqonda umahluko phakathi kwendlela yokufunda kwangaphambili (okanye i-Pavlovian) kunye nenjongo-ezijoliswe (okanye izixhobo) zokulawula ukuziphatha okunomdla. Ewe, ngokujonga ukuba ezi nkqubo zimbini ziye zadityaniswa kangaphi kuncwadi ngomvuzo, uphononongo olufutshane lwalo mahluko lubonakala luyisiqalo esiluncedo kwingxoxo yethu.

Kwimeko ye-Pavlovian ekhangayo, umvuzo (okt i-stimulus engenamiqathango okanye i-US) idityaniswe ne-stimulus (isivuseleli esinemiqathango okanye i-CS), kungakhathaliseki ukuba isilwanyana siziphatha njani, ngelixa ukufunda ngezixhobo, umvuzo uxhomekeke kwizenzo zezilwanyana. Umbuzo obalulekileyo kuzo zombini iimeko, nangona kunjalo, ingaba umbutho wokuvuselela-umvuzo okanye umbutho wokuvuza isenzo ukulawula ukuziphatha.

Njengoko kubonakala kulula, lo mbuzo awuzange uphumelele kubaphandi kumashumi eminyaka amaninzi ngenxa yokuba iimpendulo zokuziphatha kwezi meko zinokubonakala zifana.

Ke, iimpendulo ezinemiqathango (CRs) ezilawulwa yi-Pavlovian stimulus-reward association zihlala zine-veneer yenjongo-directional malunga nazo. Nokuba i-salivation, i-CR ye-Pavlov yasekuqaleni, yayinokuthi iveliswe yizinja zakhe njengenzame ngamabomu ukuququzelela ukungenisa. Kungenxa yoko le nto ingcaciso ecacileyo-ekuthi kwi-Pavlovian conditioning i-stimulus-outcome association ifundwe, ngelixa i-instrumental conditioning i-action-outcome association ifundwe-yehlulekile ukufumana inkxaso eninzi kwiminyaka emininzi (Isikhumba, i-1938; UAshby, ngo-1960; IiBolles, i-1972; IMackintosh, 1974). Nangona kunjalo, nangona ii-CRs ezininzi zePavlovian zizimele okanye zigqibezela, ezinye ii-CRs, ezinje ngokuziphatha okusingise emvuzweni, azibonakali kakuhle (Rescorla kunye noSolomon, ngo-1967); eneneni, ngokulula banokubhidaniswa nezenzo zesixhobo (UBrown noJenkins, ngo-1968; UWilliams noWilliams, ngo-1969; Schwartz noGamzu, ngo-1977). Ngoku siyazi ukuba, nangona ukufana okungaphezulu, i-Pavlovian CRs kunye neenjongo ezijoliswe kwiinjongo zezixhobo ziyahluka kwisakhiwo esimelayo esilawula ukusebenza kwempendulo (Schwartz noGamzu, ngo-1977).

Eyona ndlela ichanekileyo yokumisela ukuba ngaba ukusebenza kwempendulo kulamlwa ngumvuzo we-stimulus-award okanye i-action-reward association kukuhlola ukusebenza kokulawula okungalindelekanga. Umzekelo wokugalela amathe uyafundisa apha. Sheffield (1965) ivavanyiwe ukuba ingaba i-salivation kwi-Pavlovian conditioning yayilawulwa bubudlelwane bayo nomvuzo okanye ngombutho wokuvuselela umvuzo. Kuvavanyo lwakhe, izinja zafumana izibini phakathi kwethoni kunye nomvuzo wokutya (Sheffield, ngo-1965). Nangona kunjalo, ukuba izinja zahlutha ngexesha lethoni, ukutya akuzange kuhanjiswe kweso lingo. Eli lungiselelo lagcina ubudlelwane be-Pavlovian phakathi kwethoni kunye nokutya, kodwa laphelisa naluphi na unxulumano oluthe ngqo phakathi kwe-salivation kunye nokuhanjiswa kokutya. Ukuba isaliti yayisisenzo esilawulwa lubudlelwane bayo nokutya, ngoko ke izinja kufuneka ziyeke ukugalela amathe-eneneni akufuneki zithole isalivation kwithowuni kwaphela. USheffield wafumanisa ukuba ngokucacileyo yayiyi-Pavlovian ithoni-ubudlelwane bokutya obulawula i-salivation CR. Ebudeni bokutya okungaphezulu kwama-800, izinja ziye zafumana zaza zagcina izinkcwe kwithowuni nangona oku kubangele ukuba ziphulukane nokutya ebezinokukufumana ngokungatyi izinkcwe. Isigqibo esifanayo safikelelwa ngabanye kwizifundo nabantu (Pithers, 1985) kunye nezinye izilwanyana (UBrown noJenkins, ngo-1968; Williams & Williams, ngo-1969; eHolland, ngo-1979); kuzo zonke iimeko, kubonakala ukuba, nangona kukho ukuhlukahluka okukhulu, iimpendulo zePavlovian azilawulwa ngobudlelwane babo nomvuzo-okt yi-action-outcomency contingency.

Igama elithi imeko enokwenzeka libhekisa kubudlelwane obunemiqathango phakathi kwesiganeko 'A' kunye nesinye, 'B', kangangokuba ukwenzeka kuka-B kuxhomekeke ku-A. Ubudlelwane obulolu hlobo bunokuthotywa ngokulula ngokuthi kuboniswe u-B engekho u-A. Ukusetyenziswa kolingelo, okubhekiselwa kuko ukuthotywa okunokwenzeka, kuqhele ukwenziwa ngokunikezela ngomvuzo ngokuzimeleyo nokuba sisivuseleli esixelwe kwangaphambili okanye isenzo. Nangona le ndlela yaphuhliswa ekuqaleni ukufunda imeko yePavlovian (Rescorla, ngo-1968), ukuthotywa kwezixhobo ezinokwenzeka kuye kwaba sisixhobo esiqhelekileyo (Hammond, ngo-1980). Xa ezi ziganeko ezingalindelekanga ziphathwa ngokuthe ngqo, umxholo wokufunda utyhilwa: umz. kwi-autoshaping, i-Pavlovian CR 'efihliweyo' njengesenzo sesixhobo iphazamiseka ngokusetyenziswa kwePavlovian kunokuba i-instrumental contingency (Schwartz noGamzu, ngo-1977).

Izenzo zesixhobo ezijoliswe kwiinjongo zibonakaliswe ngeendlela ezimbini: 1) uvakalelo kwiinguqu kwixabiso lesiphumo, kunye ne-2) uvakalelo lokutshintsha kwimeko enokwenzeka phakathi kwesenzo kunye nesiphumo. (I-Dickinson, i-1985; UDickinson kunye neBalleine, i-1993). Uvakalelo lokuthotywa kwesiphumo sodwa, kufuneka kugxininiswe, akwanelanga ekuboniseni impendulo njengenjongo ejoliswe kuyo kuba ezinye iimpendulo zePavlovian nazo zinokuba novelwano kolu qheliso (IHolland kunye neRescorla, ngo-1975). Nangona kunjalo, ukusebenza kweenjongo ezijoliswe kwiinjongo zezixhobo zikwanovakalelo ekusetyenzisweni kwesiphumo sesiphumo esilindelekileyo, ngelixa iimpendulo zePavlovian zinovakalelo malunga nokunyanzeliswa kwesiphumo sokuvuselela (Rescorla, ngo-1968; UDavis noBitterman, ngo-1971; UDickinson noCharnock, ngo-1985). Imeko ebalulekileyo, nangona kunjalo, inokufumaneka kwimeko yemikhwa (jonga apha ngezantsi), efana kakhulu neempendulo zePavlovian ekungakhathaliyo kwazo kwiinguqu kwi-instrument contingency, kodwa nazo zingenakuthintelwa ukuthotywa kwesiphumo ngenxa yokuba isiphumo asiyonxalenye. yesakhiwo esimelayo esilawula ukusebenza (cf. I-Dickinson, i-1985 kwaye ngezantsi kwingxoxo eqhubekayo).

Ukushwankathela, ngoko ke, kubaluleke kakhulu ukuba impendulo ethile ichazwe ngokucacileyo kwixesha lexesha elingalindelekanga elilawulayo kunokuba mhlawumbi ifom yempendulo okanye umsebenzi wokuziphatha osetyenzisiweyo ukuseka. Ngaphandle kokuphonononga ulawulo olunokwenzeka kwimeko enikiweyo, zombini indlela yokuziphatha kunye neenkqubo ze-neural ezifunyenwe ukulamla indlela yokuziphatha kusenokwenzeka ukuba zingabhalwa ngendlela engeyiyo. Ekugqibeleni, njengoko siza kuxoxa, lolona lawulo lungalindelekanga, olufunyenwe ngokufunda nokuphunyezwa ziinkqubo zemithambo-luvo ezahlukileyo, ezilawula ukuziphatha, nangona zinokwabelana 'ngendlela yokugqibela eqhelekileyo'. Ke ngoko owona mceli mngeni uphambili kukuhamba ngaphaya kwembonakalo ukuze utyhile indlela yokuziphatha esisiseko yokulawula imeko (ukufumana isishwankathelo bona 1 Table). Ukuze wenze ibango lokuba izakheko ezithile ze-neural zilamla amandla athile engqondo, umz. ulwalathiso-njongo, ubume bokuziphatha kufuneka buvavanywe ngovavanyo lokuziphatha olufanelekileyo. Ukwenza ngenye indlela kukumema ukubhideka njengoko amaqela exoxa malunga nezikhombisi ezifanelekileyo ze-neural ngelixa esilela ukuqaphela ukuba imisebenzi yabo yokuziphatha inokuba kukulinganisa iziganeko ezahlukeneyo. Eyona nto ibalulekileyo, ekugqibeleni, yinto esiyifundayo sisilwanyana, hayi into ekholelwa ukuba isilwanyana siyayifunda, kwaye into efundwa sisilwanyana sinokutyhilwa kuphela ziimvavanyo eziphonononga ngokuthe ngqo umxholo wokufunda.

Ukwahlula kwe-Pavlovian-instrumental bekuya kuba yinto encinci, ukuba isilwanyana siyakwazi ukufunda into efanayo (thetha umbutho phakathi kwe-stimulus kunye nomvuzo) kungakhathaliseki ukuba yintoni na amalungiselelo okulinga. Ukusebenzisa awona manyathelo aqhelekileyo okufunda akhoyo kwi-neuroscience namhlanje, akukho ndlela yokuxela. Ngaloo ndlela abaphandi bahlala bebanga ukuba bafunda ukuziphatha okujoliswe kuko ngaphandle kokuvavanya ukuba ukuziphatha okubhekiselwe ngokwenene kujoliswe ekujoliswe kuyo. Nangona iindidi ezahlukeneyo zokufunda zikholisa ukucingelwa ukuba zibangelwa kukusetyenziswa 'kwemisebenzi' okanye 'ii-paradigms' ezahlukeneyo, amaxesha amaninzi abaphandi bayasilela ukubonelela ngengqiqo eyaneleyo yeengqikelelo zabo.

Umzekelo obalaseleyo walo mba kukusetyenziswa kweemaze ukufunda ukufunda. Enye ingxaki ngovavanyo lwe-maze kunye novavanyo oluhambelanayo, njengokukhethwa kwendawo emiselweyo, ubunzima bokuvavanya ukuhlukanisa impembelelo ye-Pavlovian (i-stimulus-reward) kunye nesixhobo (isenzo somvuzo) kwiimeko zokuziphatha (I-Dickinson, i-1994; I-Yin kunye ne-Knowlton, i-2002). Ke, ukuhamba nge-T-maze ukufumana ukutya kunokubonisa isicwangciso sokuphendula (jikela ngasekhohlo) okanye indlela nje ebekwe kwimeko ethile ukuya kwindawo ethile eyongezelelekileyo elawulwa lumanyano lokutya (cue-food association)Ukuphumla, ngo-1957). Enye indlela yokuvavanya ukuba ingaba le yokugqibela idlala indima na ekusebenzeni kukuguqula imaze; ngoku impendulo abafundi kufuneka baqhubeke nokujika bajike ngasekhohlo ngelixa abo basebenzisa imiqondiso engaphezulu yemaze kufuneka bajike ekunene. Kodwa ngaba abo baqhubeka bejikela ngasekhohlo ngenene besebenzisa isicwangciso sokuphendula okanye basondela nje kwezinye intra-maze cue ehambelana nokutya? Ayingomba ulula ukufumana, kuba ulawulo oluqhelekileyo lolawulo lwePavlovian lokuziphatha alunakusetyenziswa ngokulula kwizifundo zemaze. Enye yezi, ulawulo lwe-bidirectional, imisela ukuba izilwanyana zikwazi ukulawula impendulo ethile ngokufuna ukuguqulwa kolwalathiso lwaloo mpendulo ukuze ufumane umvuzo (Hershberger, ngo-1986; Heyes kunye noDawson, ngo-1990). Ngelishwa, kwi-maze, ukuguqulwa kwempendulo kusenokungonelanga ukuseka isenzo njengenjongo ejoliswe kuyo, kuba ukuguqulwa kunokufezekiswa ngokucima ubudlelwane obukhoyo kunye nokubuyisela omnye endaweni. Umzekelo, impuku esondela kwindawo ethile ye-intra-maze cue inokufunda, ngexesha lokubuyela umva, ukuba ayisadityaniswa nomvuzo, kodwa enye into evuselelayo, ekhokelela ekufumaneni indlela ye-CR ebhekiselele kwisivuseleli esitsha. Ke ngoko, banokuthi bayibuyisele umva impendulo yabo ngaphandle kokuba bafake ikhowudi yokufumana umvuzo wokuphendula. Ngenxa yokuba oku kunokwenzeka kungenakuvavanywa ngokusebenza, ukusetyenziswa kweemazes, iinkqubo zokukhethwa kwendawo, okanye imisebenzi elula ye-locomotor ukufunda iinkqubo zokufunda ezijoliswe kwiinjongo ziyingozi kakhulu kwaye zingabangela ukungahambi kakuhle kweenkqubo zokulawula ukuziphatha kunye nendima ethile yayo nayiphi na i-neural. iinkqubo ezifunyenwe zibandakanyeka (USmith-Roe noKelley, i-2000; Hernandez et al., 2002; Atallah et al., 2007).

I-Nucleus accumbens ayiyimfuneko ekufundeni izixhobo

Ukungaphumeleli kokuhlalutya kokuziphatha kwangoku kuyacaca ngokukodwa kwisifundo se-nucleus accumbens. Izifundo ezininzi zicebise ukuba esi sakhiwo sibaluleke kakhulu ekufumaneni izenzo ezijoliswe kwiinjongo (Hernandez et al., 2002; Goto noGrace, 2005; Hernandez et al., 2005; Pothuizen et al., 2005; I-Taha kunye neMimandla, i-2006; Atallah et al., 2007; I-Cheer et al., 2007; Lerchner et al., 2007). Kodwa esi sigqibo kuye kwafikelelwa kuso ngokusekwe ubukhulu becala kwimilinganiselo yotshintsho kwindlela yokusebenza yodwa, kusetyenziswa imisebenzi apho ukuziphatha kokulawula okunokwenzeka kungacacanga. Nangona uqwalaselo lokuba ukukhohlisa kuphazamisa ukufunyanwa kwempendulo ethile yokuziphatha kungabonisa ukusilela ekufundeni, banokubonisa impembelelo ekuqalisweni kwempendulo okanye inkuthazo. Ngokomzekelo, ukuphazamiseka ekufumaneni i-lever pressing kuhlala kubonisa umphumo ekusebenzeni kunokuba kufundwe (USmith-Roe noKelley, i-2000). Iijiko zokufumana izinto zodwa, njengenkcazelo engaphelelanga yayo nayiphi na inkqubo yokufunda, mazitolikwe ngononophelo (Gallistel et al., 2004). Ngelishwa, umahluko phakathi kokufunda nokusebenza, mhlawumbi esona sifundo sidala kwisifundo sokufunda, usoloko ungahoywa namhlanje.

Uhlalutyo oluneenkcukacha ngakumbi lubonisa ukuba i-accumbens ayiyomfuneko kwaye ayikwanelanga ekufundeni izixhobo. Izilonda zeqokobhe le-accumbens aziluguquli ubuntununtunu bokwenziwa komsebenzi ukuthotywa kweziphumo (de Borchgrave et al, 2002; UCorbit et al, ngo-2001) okanye ukuthotywa kwesixhobo esingalindelekanga (UCorbit et al, ngo-2001), ngelixa izilonda ze-accumbens core zifunyenwe ukunciphisa ubuntununtunu ekuhlahleni ngaphandle kokuphazamisa uvakalelo lweempuku ekuthotyweni okukhethiweyo kwimeko yesixhobo (Corbit et al., 2001). Olunye uphononongo oluvavanya isiphumo se-accumbens manipulations ekufumaneni impendulo entsha kwizifundo zokomelezwa kwemeko ziye zafumana isiphumo ekusebenzeni okunxulumene nomvuzo, ngakumbi ukongezwa kokusebenza kwe-amphetamine, kodwa hayi ekufumaneni impendulo nganye (iParkinson). kunye nabanye, ngo-1999). Ngokunjalo, uphononongo olucwangcisiweyo lukaKhadinali kunye noCheung alufumananga siphumo sezilonda eziphambili ze-accumbens ekufumaneni impendulo ye-lever press phantsi kweshedyuli eqhubekayo yokomeleza; ukufunyanwa okungalunganga kwajongwa kuphela ngokulibaziseka kokuqinisa (UKhadinali kunye neCheung, ngo-2005).

Nangona i-accumbens ingafaki i-instrumental contingency (i-Balleine & Killcross, i-1994; Corbit, Muir & Balleine, 2001), ubungqina obuninzi bubonisa ukuba inendima ebalulekileyo kwisixhobo ukwenza, indima esinokuyichaza ngcono ngoku xa sijonga umsebenzi wakutshanje. Njengoko kuqukunjelwe zizifundo ezininzi, i-accumbens ibalulekile kwiintlobo ezithile zemeko ye-Pavlovian enomdla, kwaye ilamla zombini iziphumo ezingachanekanga ezinokuthi zifumane umvuzo ekusebenzeni kwesixhobo, kunye nesiphumo esikhethekileyo ekukhetheni impendulo eveliswayo. ngeempawu ezinjalo. Izilonda ze-core, okanye i-cingulate yangaphambili, umthombo omkhulu we-cortical input kwi-core, okanye uqhawulo phakathi kwezi zakhiwo zimbini, ukuphazamisa ukufunyanwa kwendlela yokuziphatha kwePavlovian (Parkinson et al., 2000). Ukufakwa kwendawo ye-D1-efana ne-dopamine receptor antagonist okanye i-NMDA glutamate receptor antagonist ngokukhawuleza emva koqeqesho nayo iyonakalisa le ndlela yokufunda ngaphandle kokuchaphazela ukusebenza (Dalley et al., 2005). Ezi datha ziyavumelana nemilinganiselo ye kwi vivo umsebenzi we-neural. Ngokomzekelo, uCarelli kunye noogxa bafumanisa ukuba i-neurons kwi-accumbens core inokutshintsha umsebenzi wabo ngokucwangcisiweyo ngexesha lokufunda umsebenzi we-autoshaping wePavlovian (Imini et al., 2006; Usuku kunye neCarelli, 2007).

IiNeurons ezikummandla weqokobhe zibonakala zilungelelaniswe nemivuzo kunye nezivuseleli eziphikisayo, nangaphambi kwawo nawaphi na amava okufunda; bayakwazi nokuphuhlisa iimpendulo kwii-CS eziqikelela ezi ziphumo (Roitman et al., 2005). Sebenza nguBerridge kunye nabalingane, ngaphezu koko, iye yaphakamisa amathuba okuba imimandla ethile kwi-nucleus accumbens iqokobhe kunye ne-downstream ventral pallidum inokuphawulwa njenge-'hedonic hotspots.' Ezi ndawo zimodareyitha ngokuthe ngqo iimpendulo ze-hedonic ezivuzwayo, ezifana nokuphinda kusebenze. Umzekelo, ii-agonists ze-opioid receptors kule mimandla zinokukhulisa kakhulu incasa yokungena kwi-sucrose. Imimandla ehlala kwindawo ephezulu, nangona kunjalo, ifakwe kuthungelwano olubanzi olungadlali nxaxheba ekuziphatheni okunqwenelayo.I-Taha kunye neMimandla, i-2005; UPecina et al., 2006; I-Taha kunye neMimandla, i-2006).

Umahluko kwiindima ezihambelanayo zondoqo kunye neqokobhe ubonakala ungomnye phakathi kokulungiselela kunye nokuziphatha okunqwenelayo, ngokulandelelana, okunokuguqulwa ngokulula ngamava ngeentlobo ezahlukeneyo zemeko yePavlovian. Iimpendulo zolungiselelo ezifana nendlela zinxulunyaniswa neempawu zovakalelo ngokubanzi zesiphumo, kanti iindlela zokuziphatha ezigqibeleleyo zinxulunyaniswa neempawu zovakalelo ezithe ngqo; zikwachaphazeleka ngokwahlukileyo kwiintlobo ezahlukeneyo ze-CS, umz. iimpendulo ezilungiselelweyo zilungiswa ngokulula kunye nesivuseleli esinexesha elide (Konorski, ngo-1967; UDickinson kunye noDearing, ngo-1979; I-Balleine, 2001; UDickinson kunye neBalleine, i-2002).

Ngayiphi na indlela, ubungqina obubandakanya i-accumbens kwezinye iinkalo ze-Pavlovian conditioning buninzi. Nangona kunjalo, ayisiyiyo kuphela isakhiwo esibandakanyekayo, kunye nezinye iinethiwekhi, ezifana nezo zibandakanya i-nuclei ye-amygdaloid eyahlukeneyo, nazo zibonakala zidlala indima ephambili kwizinto zombini zokulungiselela kunye ne-consummatory ye-Pavlovian conditoning. (IBalleine kunye neKillcross, 2006).

Omnye umsebenzi onokuthi uchazwe ngokucacileyo kwi-accumbens ukuhlanganiswa kweempembelelo zePavlovian ekuziphatheni kwezixhobo. I-Pavlovian CRs, kubandakanywa nezo zibonakalisa ukusebenza kweendawo ezikhuthazayo eziphambili, ezifana nokukhanga kunye nokuvuswa, kunokusebenzisa impembelelo enamandla ekusebenzeni kwezixhobo zokusebenza (UTrapold noOvermier, ngowe-1972; Lovibond, ngo-1983; eHolland, ngo-2004). Ngokomzekelo, i-CS eqikelela ngokuzimeleyo ukuhanjiswa kokutya inokunyusa ukuphendula kwesixhobo sokutya okufanayo. Esi siphumo sifundwa ngokuqhelekileyo kusetyenziswa i-Pavlovian-instrumental transfer paradigm (PIT). Kwi-PIT, izilwanyana zifumana izigaba ezihlukeneyo zePavlovian kunye nezixhobo zoqeqesho, apho zifunda, ngokuzimeleyo, ukudibanisa i-cue kunye nokutya, kunye nokucinezela i-lever yokutya okufanayo. Emva koko kwiimvavanyo zeprobe, i-cue inikezelwa nge-lever ekhoyo, kwaye ukuphakama kwamazinga okuphendula phambi kwe-CS kulinganiswa. Iindlela ezimbini zePIT zichongiwe; enye inxulumene nefuthe elivuselelayo ngokubanzi lemikhombandlela enxulumene nomvuzo kunye neyesibini isiphumo esikhethiweyo ngakumbi kwintsebenzo ekhethiweyo eveliswe yimeko eqikelelweyo ye-cue ngentlonipho yomvuzo othile ngokuchasene neminye. Iqokobhe le-accumbens liyimfuneko kolu hlobo lokugqibela lukhethekileyo lwe-PIT, kodwa aluyomfuneko kuhlobo lwangaphambili, oluqhelekileyo okanye kubuntununtunu ekuthotyweni kwesiphumo; ngokuchaseneyo, izilonda ze-accumbens core zinciphisa ubuntununtunu kuzo zombini ukuhla kwesiphumo kunye nohlobo oluqhelekileyo lwe-PIT kodwa zishiya i-PIT echanekileyo kwisiphumo esithile (Corbit et al., 2001; (IBalleine kunye neCorbit, ngo-2005).

Uphononongo lwakutsha nje lunikeze ingcaciso eyongezelelekileyo kwindima yeqokobhe le-accumbens kwi-PIT ethe ngqo kwisiphumo (Wiltgen et al., 2007). Ukubonakaliswa okulawulwayo kwe-calcium esebenzayo / i-calmodulin-exhomekeke kwiprotheni kinase II (CaMKII) kwi-striatum ayizange ichaphazele i-instrumental okanye i-Pavlovian yokufunda, kodwa yacima i-PIT ethile. Le ntsilelo kwi-PIT yayingenasigxina kwaye inokuguqulwa ngokucima intetho ye-transgene kunye ne-doxycycline, ebonisa ukuba intsilelo yayinxulumene nokusebenza kuphela. Ukuphucula ngokufanelekileyo inqanaba le-CaMKII kwi-striatum ke ngoko kuthintela ugqithiselo oluchanekileyo lwesiphumo senkuthazo ukusuka kwi-Pavlovian ukuya kwinkqubo yesixhobo. Okubangela umdla kukuba, ukuguqula iCaMKII transgene kwafunyaniswa ukunciphisa ubumnandi bee-neurons kwiqokobhe le-accumbens, ngaphandle kokuchaphazela ukuhanjiswa kwe-basal okanye amandla e-synaptic.

I-dorsal striatum

I-dorsal striatum, ekwabizwa ngokuba yi-neostriatum okanye i-caudate-putamen, ifumana uqikelelo olukhulu oluvela kwinto ebizwa ngokuba yi-neocortex. Inokwahlulwa kwakhona ibe ngummandla odibeneyo, ophakathi kweempuku kunye nokuqhubekayo kunye ne-ventral striatum, kunye nommandla we-sensorimotor osecaleni. (IGroenewegen et al., 1990; UJoel noWeiner, ngo-1994). Iyonke, i-dorsal striatum ivalwa ziiseli ze-DA ezivela kwi-substantia nigra pars compacta (SNc), kwaye ifumana kuphela uqikelelo oluncinci kwi-VTA DA neurons. (UJoel noWeiner, ngo-2000). Umsebenzi wangaphambili kwi-dorsal striatum ugxile kakhulu kwindima yayo kwi-stimulus-response (SR) yokufunda umkhwa (Miller, 1981; Mhlophe, 1989). Lo mbono usekelwe kumthetho wesiphumo, ngokwendlela umvuzo owenza ngayo ukuqinisa, okanye ukuqinisa, umbutho we-SR phakathi kwe-stimuli yendalo kunye nempendulo eyenziwa ngenxa yokuba ukuthambekela ukwenza loo mpendulo kwanda phambi kwabo. ukuvuselela (I-Thorndike, 1911; Hull, ngo-1943; Miller, 1981). Ke ngoko indlela ye-corticostriatal icingelwa ukuba ilamle ukufunda kwe-SR kunye ne-DA esebenza njengophawu lokuqinisa (Miller, 1981; UReynolds kunye neWickens, 2002).

Imifuziselo ye-SR inenzuzo yokuqulatha umgaqo ophantsi wokuguqulela ukufunda kwintsebenzo. Imodeli esekelwe kwizinto ezilindelekileyo ezinxulumene nezenzo, ngokuchaseneyo, intsonkothe ​​ngakumbi kuba inkolelo ethi "Inyathelo A likhokelela kwiSiphumo O" akunyanzelekanga ukuba liguqulelwe kwisenzo (Guthrie, ngo-1935; IMackintosh, 1974); ulwazi olulolu hlobo lunokusetyenziswa kokubini ukwenza u-'A' kunye nokuphepha ukwenza u-'A'. Ngesi sizathu, iithiyori zemveli zayigatya eyona ngcaciso icacileyo-eyile yokuba izilwanyana zinokufumana isiphumo esinesiphumo esikhokelela ekuziphatheni okukhethileyo. Kumashumi ambalwa eminyaka edlulileyo, nangona kunjalo, ubone uhlaziyo olukhulu lomthetho wesiphumo (I-Adams, 1982; Colwill kunye neRescorla, ngo-1986; I-Dickinson, i-1994; UDickinson et al., 1996). TIziphumo zophononongo oluninzi zibonise ukuba izenzo zesixhobo zinokujoliswa ngokwenyani, oko kukuthi, uvakalelo kutshintsho lwexabiso lomvuzo kunye nokusebenza kakuhle kwesizathu. (jonga uDickinson & Balleine, 1994; 2002; I-Balleine, 2001 uphononongo). Nangona kunjalo, ngexesha loqeqesho olubanzi phantsi kweemeko eziqhubekayo, kwanezenzo ezisandul 'ukufunyanwa zinokuthi zizenzekele kwaye ziqhutywe-inkqubo eyaziwa ngokuba yinkqubo yesiqhelo (UAdams noDickinson, ngo-1981; I-Adams, 1982; Yin et al., 2004). Imikhwa echazwe ngolu hlobo, ikhutshwe ngokuzenzekelayo yi-stimuli yangaphambili, ayilawulwa ngokulindelekileyo okanye ukubonakaliswa kwesiphumo; ngenxa yoko abanakho ukutshintsha kwixabiso lesiphumo. Ngokwale mbono, umthetho wesiphumo ngoko ke yimeko ekhethekileyo esebenza kuphela ekuziphatheni okuqhelekileyo.

Ukuhlelwa kwangoku kwendlela yokuziphatha kwezixhobo kuyahlula ibe ziindidi ezimbini. Tiklasi yokuqala iquka izenzo ezijoliswe kwiinjongo ezilawulwa yimeko enokwenzeka; okwesibini, indlela yokuziphatha engenakukwazi ukutshintsha kwixabiso lesiphumo (1 Table). Ukusebenzisa iimvavanyo zokuziphatha ezifana nokuthotywa kwesiphumo kunye nokuthotywa kwesixhobo esinokwenzeka, u-Yin et al waseka ukwahlukana okusebenzayo phakathi kwe-sensormotor (dorsolateral striatum, DLS) kunye nemimandla yokudibanisa (i-dorsomedial striatum, i-DMS) ye-dorsal striatum.I-Yin kunye ne-Knowlton, i-2004; Yin et al., 2004, 2005a; Yin et al., 2005b; Yin et al., 2006a). Izilonda ze-DLS zonakalise ukuphuhliswa kwemikhwa, okukhokelela kwindlela yokulawula ukuziphatha okujoliswe ngakumbi. Izilonda ze-DMS zinempembelelo echaseneyo kwaye zikhokelela ekutshintsheni kwinjongo-ejoliswe kulawulo oluqhelekileyo. U-Yin et al waphetha, ngoko ke, ukuba i-DLS kunye ne-DMS inokudityaniswa ngokusebenzayo ngokubhekiselele kuhlobo lwezakhiwo ezihlangeneyo ezixhasayo: i-DLS ibaluleke kakhulu ekwenzeni umkhwa, kanti i-DMS ibaluleke kakhulu ekufumaneni nasekuboniseni izenzo ezijoliswe kwiinjongo. Olu hlalutyo luqikelela ukuba, phantsi kweemeko ezithile (umz. uqeqesho olwandisiweyo) ulawulo lwezenzo lunokutshintsha ukusuka kwinkqubo exhomekeke kwi-DMS ukuya kwinkqubo exhomekeke kwi-DLS, isiphelo esivumelana ngokubanzi kunye noncwadi olubanzi kwiiprimates, kubandakanywa ne-neuroimaging yabantu.Hikosaka et al., 1989; Jueptner et al., 1997a; UMiyachi et al., ngo-1997; UMiyachi et al., ngo-2002; Delgado et al., 2004; UHaruno et al., 2004; Tricomi et al., 2004; Delgado et al., 2005; Samejima et al., 2005; IHaruno kunye neKawato, ngo-2006a, b; Lohrenz et al., 2007; UTobler et al., 2007). Kufuneka kukhunjulwe, kunjalo, tindawo ekhoyo yomnqwazi (umz. idorsal okanye i-ventral) iyodwa ayinakuba sisikhokelo esithembekileyo ekuthelekiseni i-rodent striatum kunye neprimate striatum; uthelekiso olunjalo kufuneka lwenziwe ngononophelo, emva kokuqwalaselwa ngokucophelela koqhagamshelwano lwe-anatomical.

Iziphumo zezilonda ze-dorsal striatal zinokuthelekiswa nezo zezilonda ze-accumbens (USmith-Roe noKelley, i-2000; Atallah et al., 2007). Njengoko sele kukhankanyiwe, iimvavanyo ezisemgangathweni zokuseka indlela yokuziphatha 'njengejolise kwinjongo' kukuthotywa kweziphumo kunye nokuthotywa kwemeko elindelekileyo yesiphumo (action-outcome contingency).UDickinson kunye neBalleine, i-1993). Izilonda ze-DMS zenza ukuba ukuziphatha kungabi naluvelwano kuzo zombini ezi nguqulelo (Yin et al., 2005b), ngelixa izilonda ze-accumbens core okanye iqokobhe azenzi (Corbit et al., 2001). Ngaphaya koko, iimvavanyo zeprobe zolu vavanyo lokuziphatha luqhutywa ngokuphela, ngaphandle kokunikezelwa kwawo nawuphi na umvuzo, ukuze kuvavanywe ukuba isilwanyana sifunde ntoni ngaphandle kokungcoliswa kukufunda okutsha. Baphonononga ngokuthe ngqo ubume bomelo obulawula ukuziphatha. Njengolawulo olongezelelekileyo lovavanyo, kudla ngokuba luncedo ukwenza uvavanyo olwahlukileyo lokuthotywa ixabiso apho imbuyekezo inikezelwa ngokwenene-into ebizwa ngokuba 'luvavanyo oluvuzayo.' Izilonda ze-DMS azizange ziphelise ubuntununtunu kwisiphumo sokuthotywa kwexabiso kuvavanyo oluvuzwayo, njengoko kufanele kulindelwe ukususela ekubeni ukunikezelwa kwesiphumo esincitshisiweyo esixhomekeke kwisenzo sinokucinezela isenzo ngokuzimeleyo kwi-encoding ye-action-outcomed. I-Accumbens izilonda zegobolondo, kwelinye icala, ayizange iphazamise ubuntununtunu ekuhlalutyweni kwesiphumo nokuba kuvavanyo lokutshabalala okanye uvavanyo oluvuzayo, ngelixa i-accumbens izilonda ezingundoqo ziphelise ubuntununtunu bokunciphisa ixabiso kuzo zombini iimvavanyo (Corbit et al., 2001). Uvakalelo lokuthotywa okunokwenzeka, nangona kunjalo, akuzange kuchaphazeleke nokuba sesiphi isilonda, nto leyo ebonisa ukuba, emva kwezilonda eziqokeleleneyo, iimpuku zikwazile ukubethelela kunye nokubuyisela imiboniso yeziphumo zentshukumo.

Indima ye-dopamine: i-Mesolimbic vs. nigrostriatal

Ukusukela oko kusenziwa izifundo zobuvulindlela kumsebenzi we-phasic we-DA neurons kwiinkawu, ukucinga okuqhelekileyo kwintsimi kukuba zonke iiseli ze-DA ziziphatha ngendlela efanayo.Schultz, 1998a; UMontague et al., 2004). Nangona kunjalo, idatha ekhoyo, kunye noqhagamshelwano lwe-anatomical, lucebisa ngenye indlela. Ngapha koko, uhlalutyo olungentla lwe-heterogeneity esebenzayo kwi-striatum inokwandiswa kwiiseli ze-DA kwi-midbrain ngokunjalo.

Iiseli ze-DA zinokwahlulwa zibe ngamaqela amabini amakhulu: i-VTA kunye ne-substantia nigra pars compacta (SNc). Nangona ingqikelelo evela kwi I-VTA to accumbens ibe liziko lengqwalasela kwinkalo yokufunda enxulumene nomvuzo, eyona ndlela inkulu ye-nigrostriatal ayihoywanga., ingqalelo ejoliswe ngokuyintloko kwindima yayo kwisifo sikaParkinson. Ukucinga kwangoku ngendima ye I-DA ekufundeni iye yaphenjelelwa kakhulu sisindululo sokuba umsebenzi we-phasic weeseli ze-DA ubonisa i-erro yokubikezela umvuzo.r (I-Ljungberg et al., 1992; Schultz, 1998b). Mnan owona msebenzi uqhelekileyo we-Pavlovian conditioning osetyenziswa nguSchultz kunye noogxa, ezi neurons zivutha umlilo ekuphenduleni umvuzo (US) kodwa, ngokufunda, umsebenzi okhutshwe e-US utshintshelwe kwi-CS. Xa i-US ishiywe emva kokufunda, iiseli ze-DA zibonisa ukudakumba okufutshane kumsebenzi ngexesha elilindelekileyo lokunikezelwa kwayo (I-Waelti et al., 2001; UFiorillo et al., 2003; UTobler et al., 2003). Ezo datha zenza isiseko seemodeli ezahlukeneyo zokubala (Schultz et al., 1997; Schultz, 1998b; Brown kunye al., 1999; UMontague et al., 2004).

Ukunikezelwa kwamanqanaba amaninzi olawulo kwiindlela zokwenziwa kunye nokukhululwa, i-spiking ye-DA neurons ayinakulinganiswa nokukhululwa kwe-DA, nangona umntu unokulindela ukuba le milinganiselo mibini idityaniswe kakhulu. Ewe, njengoko kubonisiwe kuphononongo lwakutsha nje olwenziwa nguCarelli kunye noogxa basebenzisa i-voltammetry ekhawulezayo yokuskena, Ukukhutshwa okwenyani kwe-DA kumbindi we-accumbens kubonakala kunxibelelene nempazamo yokuxela kwangaphambili kwimeko yePavlovian enomdla. (Imini et al., 2007). Bafumene umqondiso we-phasic we-DA kumbindi we-accumbens kwangoko emva kokufumana umvuzo we-sucrose kwi-autoshaping yasePavlovian. Emva kwemeko eyandisiweyo yePavlovian, nangona kunjalo, lo mqondiso awuzange ufunyanwe emva komvuzo ngokwawo, kodwa watshintshela kwi-CS endaweni yoko.. Oku kufunyanisiweyo kuxhasa uqikelelo 'lweprediction error' yokuqala. Kwakhona kuhambelana nomsebenzi wangaphambili obonisa ukusebenza kakubi kwePavlovian CR emva kokuba i-DA receptor antagonism okanye i-DA iyancipha kwi-accumbens core (Di Ciano et al., 2001; Parkinson et al., 2002). Nangona kunjalo, uqwalaselo olunye oluvela kwisifundo lutsha kwaye lunomdla omkhulu: emva kokumiswa kwemeko eyandisiweyo kunye ne-CS + eqikelela umvuzo kunye ne-CS- engenakuqikelela umvuzo, okufanayo, nangona kuncinci, umqondiso we-DA wabonwa emva kwe-CS-, nangona kunjalo. iphinde yabonisa ukuntywila okuncinci kwangoko (500 ~ 800 millisecond emva kokuqala kwecue) emva kwencopho yokuqala (Usuku et al, 2007, Umfanekiso 4). Ngeli nqanaba lokufunda, izilwanyana phantse azisondeli kwi-CS−, kodwa zihlala zisondela kwi-CS+. Ngaloo ndlela umqondiso we-DA we-phasic ngokukhawuleza emva kokuba i-predictor ayinakudlala indima ye-causal ekuveliseni impendulo yendlela, kuba ikhona nangona ukungabikho kwempendulo. Ukuba olo phawu lusafuneka na ukuze kufundwe imeko ye-stimulus-woward contingency kuhlala kungacaci, kodwa impendulo ye-phasic eqatshelweyo kwi-CS- ngokuqinisekileyo ayiqikelelwanga yiyo nayiphi na imodeli yangoku.

Okubangel 'umdla kukuba, ukucutheka kwe-DA yendawo kuyonakalisa ukusebenza kwalo msebenzi (Parkinson et al., 2002). Ngelixa umqondiso we-phasic weDA ubonwa emva kwe-CS-, engavelisi ii-CRs kwaphela, ukuphelisa zombini i-phasic kunye ne-tonic DA ngokuncipha kwendawo kuyonakalisa ukusebenza kwee-CRs. Umzekelo onjalo ubonisa ukuba i-phasic DA isignali kwi-accumbens ayidingeki ekusebenzeni kwe-Pavlovian CR, kodwa inokudlala indima ekufundeni, ngelixa i-sounder ecothayo, i-tonic ye-DA yesiginali (ekusenokwenzeka ukuba yapheliswa kwizifundo zokunciphisa) ibaluleke kakhulu ekusebenzeni. yempendulo yendlela (Cagniard et al., 2006; Yin et al., 2006b; I-Niv et al., 2007). Oku kunokwenzeka kusaza kuvavanywa.

Nangona kungekho bungqina buthe ngqo bendima eyi-causal ye-phasic signal ye-DA ekufundeni, ingqikelelo ethi 'prediction error' nangona kunjalo itsalele ingqalelo enkulu, kuba kanye kanye luhlobo lwemiqondiso yokufundisa esetyenziswa kwiimodeli eziphambili zokufunda, njengemodeli yeRescorla-Wagner kunye nolwandiso lwexesha lokwenyani umahluko wexeshana wokomeleza ialgorithm yokufunda (Schultz, 1998b). Ngokwale toliko, ukufunda ngokungxama kumiselwa ngumahluko phakathi komvuzo ofunyenweyo nolindelweyo (okanye phakathi koqikelelo lwemivuzo emibini elandelelanayo okwethutyana). Umqondiso onjalo wokufundisa ulawulwa yingxelo engalunganga evela kubo bonke abaqikeleli bomvuzo (Schultz, 1998b). Ukuba akukho mvuzo ulandela i-predictor, emva koko indlela yempendulo engalunganga iyatyhilwa njengediphu kumsebenzi we-DA neurons. Ke ngoko, ukufunda kubandakanya ukucutha okuqhubekayo kwempazamo yokuqikelela.

Ubuhle bomqondiso wokufundisa kule mifuziselo mhlawumbi bubaphazamisile abanye kwinyani ye-anatomical. Kuphononongo ngo Usuku et al (2007), isibonakaliso se-DA kwi-accumbens sivela kakhulu kwiiseli ze-VTA, kodwa kubonakala kungenakwenzeka ukuba ezinye iiseli ze-DA, ezinoqhagamshelwano oluhluke ngokupheleleyo lwe-anatomical, zingabonisa iprofayili yokuphendula efanayo kwaye zinike uphawu olufanayo. I-gradient kwinto enokwenzeka kwiiseli ze-DA, kuba iiseli ze-DA ziprojekthi kwiindawo ezahlukeneyo zokuzala ezinemisebenzi eyahluke ngokupheleleyo, kwaye zifumana, ngokulandelelana, izibonakaliso zempendulo ezingalunganga ezivela kwimimandla eyahlukeneyo yokubetha.UJoel noWeiner, ngo-2000; Wickens et al., 2007). Iindlela zokuthatha kunye nokuthotywa, kunye ne-presynaptic receptors ezilawula ukukhutshwa kwe-dopamine, zikwabonisa umahluko omkhulu kwi-striatum (UCragg et al., ngo-2002; Irayisi kunye neCragg, ngo-2004; Wickens et al., 2007; Irayisi kunye neCragg, ngo-2008).

Siphakamisa, ke ngoko, ukuba indlela ye-mesoaccumbens idlala indima ethintelweyo ngakumbi ekufundeni kwePavlovian, ekufumaneni ixabiso lamazwe kunye ne-stimuli, ngelixa indlela ye-nigrostriatal ibaluleke kakhulu ekufundeni kwezixhobo, ekufumaneni ixabiso lezenzo. TUmnqwazi kukuba, umqondiso we-phasic weDA unokufakela iimpazamo ezahlukeneyo zokuxela kwangaphambili, kunempazamo enye yoqikelelo, njengoko kucingelwa ngoku. Iindlela ezintathu zobungqina ezixhasa le ngxoxo. Okokuqala, ukuchithwa kofuzo lwe-DA kwindlela ye-nigrostriatal yonakalisa ukufunyanwa kunye nokusebenza kwezenzo zezixhobo, ngelixa ukuchithwa kwe-DA kwindlela ye-mesolimbic (I-Sotak et al., 2005; URobinson et al., 2007). Okwesibini, iiseli ze-DA kwi-SNc zinokufaka ikhowudi yexabiso lezenzo, ezifana neeseli ezikummandla wazo wokubethelela (UMorris et al., 2006). Okwesithathu, isilonda esikhethiweyo se-nigrostriatal projection ukuya kwi-DLS yonakalisa ukwakheka komkhwa (Faure et al., 2005).

Umsebenzi wakutsha nje kaPalmiter kunye noogxa babonise ukuba iimpuku ezinqongopheleyo ze-DA ezenziwe ngofuzo ziphazamiseke kakhulu ekufundeni kwezixhobo kunye nokusebenza, kodwa ukusebenza kwazo kunokubuyiselwa ngenaliti ye-L-DOPA okanye ngokugqithiselwa kofuzo lwentsholongwane kwindlela ye-nigrostriatal.I-Sotak et al., 2005; URobinson et al., 2007). Ngokwahlukileyo, ukubuyiselwa kwe-DA kwi-ventral striatum bekungeyomfuneko ukubuyisela isimilo sezixhobo. Nangona indlela imiqondiso ye-DA ikwenza ngayo ukufunda ngezixhobo ihleli ingumbuzo ovulelekileyo, enye into enokwenzeka ecacileyo kukuba inokubethelela ixabiso lezenzo zokuzenzela, okt ungakanani umvuzo oqikelelweyo xa kunikwa ikhondo elithile lesenzo.

I-dorsal striatum, iyonke, iqulethe ukubonakaliswa okuphezulu kwe-DA receptors kwingqondo, kwaye ifumana eyona projekthi inkulu ye-dopaminergic.. Uqikelelo lwe-DA kwi-DMS lunokudlala indima eyahlukileyo ekufundeni kunoqikelelo lwe-DLS, njengoko le mimandla mibini ihluke kakhulu kwiprofayili yexeshana yokukhululwa kwe-DA, ukuthathwa, kunye nokuthotywa.Wickens et al., 2007). Siqikelela ukuba uqikelelo lweDA oluya kwi-DMS olusuka kwi-medial SNc lubaluleke kakhulu kwisiphumo sokufunda, kanti uqikelelo lwe-DA oluya kwi-DLS olusuka kwi-lateral SNc lubalulekile ekwenzeni umkhwa. Ukuba oku kuyinyani, umntu kufuneka alindele iiseli ze-DA kwi-SNc ukuba zifake impazamo kwingqikelelo yomvuzo esekwe kwizenzo ezenziweyo-impazamo yesixhobo sokuxela kwangaphambili-kunokuba isekwe kwi-CS. Ubungqina bokuqala bokuxhasa eli bango buvela kuphononongo olutshanje lukaMorris et al, orekhode kwi-SNc neurons ngexesha lomsebenzi wokufunda wezixhobo (UMorris et al., 2006). Iinkawu zaqeqeshelwa ukuhambisa iingalo zazo ngokusabela kwimpembelelo yocalucalulo (S^D) ebonisa intshukumo efanelekileyo kunye nokuba nokwenzeka komvuzo. I-S^D Ukwenziwa komsebenzi we-phasic kwi-DA neurons ehambelana nexabiso lesenzo ngokusekelwe kumvuzo olindelekileyo wesenzo esithile. Eyona nto inika umdla, nangona impendulo yeDA kwi-S^D inyuswe ngexabiso lesenzo, i-inverse yayiyinyani yempendulo ye-DA kumvuzo ngokwawo, ngokuhambelana nombono wokuba ezi neurons zifakela impazamo yokuxela kwangaphambili ehambelana nelo xabiso. Akumangalisi ukuba, eyona nto iphambili ekujoliswe kuyo kwezi seli, i-caudate nucleus, yaziwa ngokuba inee-neuron ezifaka amaxabiso esenzo.Samejima et al., 2005). Kufuneka kuqatshelwe, nangona kunjalo, ukuba olu phononongo aluzange lusebenzise imisebenzi yokuziphatha evavanya ngokungathandabuzekiyo ixabiso lezenzo. Uqikelelo olucacileyo lwemodeli yethu kukuba umsebenzi we-phasic we-DA uya kukhapha ukwenziwa kwezenzo, nokuba kungabikho i-S ecacileyo.^D. Umzekelo, siqikelela ukudubula kwe-nigral DA neurons ngexesha lokuzenzela umvuzo.

Ngokombono wethu, ngelixa i-mesoaccumbens i-signal ye-DA ibonisa ixabiso le-CS, isibonakaliso se-nigrostriatal, mhlawumbi ukusuka kwezo neurons ezijoliswe kwi-DMS, zibonisa ixabiso lesenzo ngokwalo, okanye nayiphi na i-S^D eliqikelela eli xabiso. Ngaphezu koko, zombini izixhobo kunye nokufunda kwePavlovian kubonakala kubandakanya uhlobo oluthile lwengxelo engalunganga yokulawula umqondiso wokufundisa osebenzayo. Ngapha koko, uqikelelo oluthe ngqo ukusuka kwi-striatum ukuya kwi-Midbrain DA neurons (Umzobo 2) kudala kucetywayo njengokuphunyezwa kwe-neural yolu hlobo lwengxelo engalunganga (IHouk et al., 1995), kunye namandla kunye nendalo yegalelo le-inhibitory inokwahluka kakhulu ukusuka kummandla ukuya kummandla.

  

Umzobo 2

Uthungelwano lwe-cortico-basal ganglia

Impazamo yokuqikelela, ngokweemodeli zangoku, luphawu lokufundisa olumisela ukuba kungakanani na okwenzekayo ekufundeni. Okoko kusekho, ukufunda kuyaqhubeka. Nangona kunjalo ngokucacileyo eli bango libonakala, impazamo yokuxela kwangaphambili ngexabiso lesenzo, nangona i-syntactically ifana nempazamo ye-Pavlovian yokubikezela, ineempawu ezizodwa ezingakhange zihlolwe ngokubanzi. Kwiimodeli zemveli ezifana nemodeli ye-Rescorla-Wagner, ejongene ngokukodwa ne-Pavlovian conditioning (nangona inempumelelo encinci), into ephambili yimpendulo engalunganga elawula impazamo yokuxela kwangaphambili. Esi siphumo simele uqikelelo olufunyenweyo, ngakumbi ngakumbi isixa yazo zonke iziqikelelo zangoku, njengoko zibanjiwe yi-compound stimuli eqhelekileyo esetyenziswa ekuthinteleni imifuniselo (Rescorla, ngo-1988). Sesi sishwankathelo soqikelelo olukhoyo lokuseka igama leempazamo zehlabathi elilelona litsha liphambili kolu didi lwemodeli. Kwizinto ezenziwayo, nangona kunjalo, amagama eempazamo zomntu ngamnye abonakala enokwenzeka ngakumbi, kuba kunzima ukubona ukuba ingxelo engalunganga ingabonisa njani ixabiso lezenzo ezininzi ngaxeshanye xa inyathelo elinye kuphela elinokwenziwa ngexesha. Kakade ke, zininzi izisombululo ezinokubakho. Umzekelo, unikwe ilizwe elithile (eliphunyezwe ngovavanyo nguS^D), iikhosi ezinokwenzeka zezenzo zinokubonakaliswa ngaxeshanye njengoqikelelo olufunyenweyo. Kodwa ubunzima obuphambili ngeempazamo zokuxela kwangaphambili kunento yokwenza nobume besenzo ngokwaso. Ukubikezelwa kwePavlovian ngokuzenzekelayo kulandela ukunikezelwa kwe-stimulus, ezimeleyo kwi-organism. Impazamo yoqikelelo lwesixhobo kufuneka ijongane nesiqalelo solawulo, kuba uqikelelo ngokwalo luxhomekeke kwintshukumo, kwaye isenzo esicingisisiweyo sikhutshwa ngokuzenzekela ngokusekwe ekusukeleni kwezilwanyana iziphumo zokwenza endaweni yokuba kuthiwe thaca sisivuseleli sangaphambili. Ekugqibeleni, ngokuchanekileyo kukungahoywa ngokubanzi kwemvelo ezenzekelayo yezenzo ezijoliswe kwiinjongo, kwi-neuroscience kunye ne-psychology, eye yaphazamisa ukuhlukana phakathi kwePavlovian kunye neenkqubo zokufunda izixhobo, kunye nohlobo lweempazamo zokubikezela ezibandakanyekayo. Kuhlala kusekwa, ke ngoko, ukuba luhlobo luni lwesignali yengxelo engalunganga, ukuba ikhona, elawula ukufunyanwa kwamaxabiso entshukumo (I-Dayan kunye neBalleine, 2002).

Okokugqibela, umsebenzi wamva nje ubandakanye uqikelelo lwe-nigrostriatal ukusuka kwi-SNc esecaleni ukuya kwi-DLS ngokukodwa kulwakhiwo lwesiqhelo. UFaure et al ukhethe ngokukhetha iiseli ze-DA ezibonisa i-DLS usebenzisa i-6-OHDA, kwaye wafumanisa ukuba oku kukhohlisa kunempembelelo encinci kwisantya sokucinezela i-lever, nangona kuphazamisa ukwakheka komkhwa, njengoko kulinganiswe kusetyenziswa ukuthotywa kwesiphumo.Faure et al., 2005). Okokuthi, izilwanyana ezinobungozi ziphendule ngendlela ejoliswe kuyo, nangona, kwiqela lolawulo, uqeqesho lwavelisa ukuziphatha okungaqhelekanga okungenakuvakalelwa kwisiphumo sokunciphisa ixabiso. Ukuncipha kwe-DA yendawo, ke, kuyafana nezilonda ze-excitotoxic ze-DLS, ekubeni zombini ubuqhetseba bubuyisela umva ukubunjwa komkhwa kwaye sithanda ukufunyanwa kwezenzo ezijolise ngqo (Yin et al., 2004). Umqondiso we-phasic we-DA obaluleke kakhulu ekubunjweni komkhwa sele uchazwe kakuhle ngumqondiso wokuqiniswa okusebenzayo kwi-algorithms yokufunda yokuqinisa yangoku yesikhashana ephefumlelwe ngumsebenzi kaHull kunye neSpence (Hull, ngo-1943; Isikhala, 1947, 1960; I-Sutton kunye neBarto, i-1998).

Cortico-basal ganglia networks

Ukuza kuthi ga ngoku sixoxe nge-heterogeneity esebenzayo ngaphakathi kwe-striatum, kodwa kuya kuba kulahlekisa ukucebisa ukuba nayiphi na indawo yokulala inokuthi, iguqulele isiphumo esilindelekileyo kwintsebenzo yesenzo ngokwayo. Endaweni yoko i-cerebral hemispheres iququzelelwe njengeeyunithi eziphindaphindayo ezisebenzayo ezibandakanya i-cortico-basal ganglia networks (Swanson, 2000; I-Zahm, 2005). Ti-striatum, isisikhululo sokungena kuyo yonke i-basal ganglia, isebenza njengendawo ekhethekileyo kwi-cortico-basal ganglia network motif, ekwaziyo ukudibanisa i-cortical, ithalamic, kunye ne-midbrain inputs.. Njengoko kuchaziwe ngasentla, nangona sisakhiwo esiqhubekayo, imimandla eyahlukeneyo yokubetha ibonakala ithatha inxaxheba kuthungelwano olusebenzayo olucacileyo, umzekelo, i-accumbens isebenza njenge-hub kwinethiwekhi ye-limbic kunye ne-DLS kwinethiwekhi ye-sensorimotor. Ngenxa yepropathi ephinde yangena yothungelwano olulolu hlobo, nangona kunjalo, akukho nxalenye yolu lwakhiwo inyuka okanye isezantsi kuyo nayiphi na ingqiqo epheleleyo; umz. inkqubo yethalamocortical zombini ingumthombo wegalelo elikhulu kwi-striatum kunye nokujoliswe kuko kuzo zombini iindlela ze-striato-pallidal kunye ne-striato-nigral.

Nangona i-parallel reentrant basal ganglia loops kudala iqatshelwa (UAlexander et al., 1986), sigxininisa iindima ezisebenzayo ezicacileyo zezi zijikelezo ngokusekelwe kwizakhiwo zokumela ezichazwe ngokusebenzayo kunye nokusebenzisana phakathi kweesekethe ekuveliseni ukuziphatha okudibeneyo. Ngesi siseko, ubuncinci ubunenethiwekhi obunjalo bunokuqondwa: uthungelwano lwe-limbic olubandakanya igobolondo kunye nengundoqo ye-accumbens ngokulandelanayo, inethiwekhi yokudibanisa ebandakanya i-associative striatum (DMS), kunye nenethiwekhi ye-sensorimotor ebandakanya i-sensorimotor striatum (DLS). Imisebenzi yabo isusela kulawulo lwe-Pavlovian URs kunye neeCRs ukuya kwizenzo zezixhobo (Umzobo 1).

  

Umzobo 1

Imimandla esebenzayo ye-striatum. Umzekeliso we-striatum ovela kwicandelo le-coronal ebonisa isiqingatha sobuchopho (Paxinos kunye noFranklin, ngo-2003). Qaphela ukuba le mimandla emine esebenzayo i-anatomically eqhubekayo, kwaye ihambelana ngokumalunga nantoni ...

Njengoko sele kukhankanyiwe, i-ventral striatum ibandakanya ubukhulu becala i-nucleus accumbens, enokwahlulwa ngakumbi kwiqokobhe kunye nombindi, nganye ithatha inxaxheba kuthungelwano olusebenzayo oluhlukileyo. Uqikelelo lwe-cortical (glutamatergic) kwiqokobhe luvela kwi-infralimbic, embindini kunye ne-lateral orbital cortices, ngelixa uqikelelo oluya kumbindi luvela kwimimandla engaphezulu ye-dorsal midline ye-prefrontal cortex njenge-ventral kunye ne-dorsal prelimbic kunye ne-cingulate cortices yangaphambili (IGroenewegen et al., 1990; I-Zahm, 2000, 2005). Ngaphakathi kwale misebenzi yothungelwano ubungqina obuhlaziyiweyo ngasentla bucebisa ukuba iqokobhe libandakanyeka kwii-URs ukuvuza kunye nokufumana ii-CRs ezipheleleyo; undoqo kwindlela yokuziphatha yokuhlola, ngakumbi ukufunyanwa kunye nokubonakaliswa kweempendulo zendlela yePavlovian. Ubuncinci ezimbini iinethiwekhi ezinkulu, ke, zinokuqondwa ngaphakathi kwenethiwekhi enkulu ye-ventral okanye i-limbic cortico-basal ganglia, enye yeyokuqukumbela kwaye enye kukuziphatha okuzilungiselelayo kunye nokuguqulwa kwabo yiPavlovian conditioning.Umzobo 1).

I-dorsal striatum ngokunjalo inokwahlulwa ibe yimimandla emibini engundoqo, i-associative kunye ne-sensorimotor, enothungelwano olusebenzayo olwahlukileyo olunxulunyaniswa nenye. I-Associative striatum (i-caudate kunye neenxalenye ze-anterior putamen kwi-primates) iqulethe i-neurons evuthayo ngokulindela imbuyekezo exhomekeke ekuphenduleni kunye nokutshintsha ukudubula kwabo ngokobukhulu bomvuzo olindelekileyo (Hikosaka et al., 1989; Hollerman et al., 1998; Kawagoe et al., 1998). Kwinethiwekhi yokudibanisa, i-cortices ye-prefrontal kunye ne-parietal association kunye nokujoliswe kuyo kwi-DMS ibandakanyeka kwimemori yesikhashana, zombini ezilindelekileyo, ngendlela yeziphumo ezilindelekileyo, kunye ne-retrospective, njengerekhodi yeekopi zamva nje (Konorski, ngo-1967). Inqanaba le-sensorimotor, ngakolunye uhlangothi, liquka i-cortices ye-sensorimotor kunye neethagethi zabo kwi-basal ganglia. Iziphumo zale sekethi zijoliswe kwii-motor cortices kunye ne-brain stem motor networks. Umsebenzi we-Neural kwi-sensorimotor striatum ayisoloko imodareyithwa ngumvuzo olindelekileyo, ibonisa umsebenzi onxulumene nentshukumo kune-neurons kwi-associative striatum.Kanazawa et al., 1993; Kimura et al., 1993; Costa et al., 2004). Ekugqibeleni, ukongeza kwi-medial-lateral gradient, kukho i-heterogeneity ebalulekileyo esebenzayo ecaleni kwe-anterior-posterior axis ye-dorsal striatum, nangona kungekho datha yaneleyo ekhoyo ngoku ukuvumela naluphi na ulwahlulo olucacileyo (Yin et al., 2005b).

Izifundo ukuza kuthi ga ngoku zijolise kuphela kumalungu e-cortical kunye ne-striatal ezi nethiwekhi. Ngokubanzi, izilonda zommandla we-cortical zineziphumo ezifanayo njengezilonda ekujoliswe kuzo ngokubetha (I-Balleine kunye ne-Dickinson, i-1998; I-Corbit kunye neBalleine, 2003; Yin et al., 2005b). Kodwa amanye amacandelo kuthungelwano anokugcina imisebenzi efanayo. Ngokomzekelo, izilonda ze-nucleus ephakathi ye-thalamus, icandelo le-intanethi ye-associative, zifunyenwe ukuphelisa uvakalelo lokuthotyelwa kwesiphumo kunye nokuthotywa kwemeko yengozi ngendlela efanayo kunye nezilonda kwi-DMS kunye ne-prelimbic cortex.Corbit et al., 2003). Ngaloo ndlela nangona imodeli yethu ngokubanzi iqikelela ukusilela kokuziphatha okufanayo emva komonakalo kwicandelo ngalinye lenethiwekhi, iphinda iphakamise, nakwesiphi na isakhiwo esinikwe njenge-pallidum okanye i-thalamus, imimandla emininzi esebenzayo.

Intsebenziswano phakathi kothungelwano

Ngaphantsi kweemeko ezininzi, ukufunda kwePavlovian kunye nezixhobo kubonakala kwenzeka ngokufanayo. I-Phenomena efana ne-PIT, nangona kunjalo, ibonisa ukuba ezi nkqubo zahlukileyo zinokusebenzisana kangakanani. Emva kokuchaza iinkqubo zokusebenza ezizimeleyo, inyathelo elilandelayo kukuqonda ukuba ezi nkqubo zilungelelaniswe njani ukuvelisa indlela yokuziphatha. Esinye isiphakamiso esinomtsalane, ngokuhambelana nomsebenzi wamva nje we-anatomical, kukuba uthungelwano oluchazwe ngasentla lucwangciswe ngokoluhlu, ngalinye lisebenza njenge-labile, umlamli osebenzayo kuluhlu lwemigangatho, evumela ulwazi ukuba lusasazeke ukusuka kwelinye inqanaba ukuya kwelinye. Ngokukodwa, unxibelelwano olusandul 'ukufunyanwa phakathi kwe-striatum kunye ne-midbrain lucebisa umbutho we-anatomical onokuthi uphumeze intsebenziswano phakathi kwenethiwekhi.Umzobo 2). Njengoko kuphawulwe nguHaber kunye noogxa bakhe, i-neuron ebulalayo ithumela uqikelelo oluthe ngqo lwe-inhibitory kwi-DA neurons apho bafumana khona uqikelelo lwe-DA, kunye neprojekthi kwii-neuron ze-DA ezithi zona ziqhubele phambili kwindawo eyahlukileyo.Haber et al., 2000). Olu qikelelo luvumela ukusasazwa kwangaphambili kolwazi kwicala elinye kuphela, ukusuka kuthungelwano lwe-limbic ukuya kuthungelwano oludibeneyo kunye ne-sensorimotor. Ngokomzekelo, uqikelelo lwePavlovian (ixabiso elifunyenweyo le-CS) linokunciphisa umqondiso wokufundisa osebenzayo kwinqanaba le-limbic, ngelixa ngokuhambelanayo kunokwenzeka ukuba umqondiso we-DA kwinqanaba elilandelayo. Ukucinywa komqondiso wokufundisa osebenzayo ngokuqhelekileyo kuphunyezwa ngumqondiso wengxelo engeyiyo kusetyenziswa uqikelelo oluthintelayo, umzekelo, ukusuka kwi-GABAergic medium spiny projection neurons ukusuka kwi-striatum ukuya kwi-DA neurons. Okwangoku, njengoko kucetyisiwe ngumbutho we-anatomical (Haber et al., 2000; Haber, 2003), ukubakho komqondiso we-DA kuthungelwano lwe-cortico-basal ganglia engummelwane (inqanaba elilandelayo kuluhlu lwemigangatho) lunokuphunyezwa ngoqikelelo lwe-disinhibitory (okt i-GABAergic striatal projection neurons ukuya kwi-nigral GABAergic interneurons kwi-DA neurons). Ngaloo ndlela, ixabiso elifundiweyo lenethiwekhi ye-limbic inokudluliselwa kwinethiwekhi ye-associative, evumela ukulungelelaniswa kokuziphatha ukuba kuhlanjululwe kwaye kwandiswe ngokuphindaphindiweyo (UAshby, ngo-1960). Lo mzekelo uqikelela, ke ngoko, ukubandakanyeka okuqhubelekayo kweenethiwekhi ezahlukeneyo ze-neural ngexesha lamanqanaba ahlukeneyo okufunda, ingcebiso exhaswa ziidatha ezahlukeneyo (Jueptner et al., 1997b; UMiyachi et al., ngo-1997; UMiyachi et al., ngo-2002; Yin, 2004; Everitt kunye noRobbins, i-2005; I-Yin kunye ne-Knowlton, i-2005; Belin kunye ne-everitt, i-2008).

I-Phenomena efuna ukusebenzisana kweenkqubo ezisebenzayo ezicacileyo, ezifana ne-PIT, zibonelela ngendawo yokuvavanya echumileyo kwiimodeli zolu hlobo. Ngokwenene, imodeli yoluhlu lwemigangatho ihambelana neziphumo zovavanyo zakutsha nje kwi-PIT. Ngokwemodeli, ukusebenzisana kwe-Pavlovian-isixhobo kulamlwa lunxibelelwano olubuyiselanayo phakathi kwe-striatum kunye ne-DA neurons. I-DA ibonakala ibaluleke kakhulu ekutshintsheni ngokubanzi, okupheliswa ngabachasi be-DA kunye nokungasebenzi kwendawo ye-VTA (UDickinson et al., 2000; Murschall kunye noHauber, ngo-2006); ngelixa ukufakwa kwendawo ye-amphetamine, enokuthi inyuse amanqanaba e-DA, kwi-accumbens inokuphucula kakhulu (Wyvell noBerridge, i2000). Kwelinye icala, indima ye-ventral striatal dopamine kudluliselo oluthile ayicacanga kangako. Obunye ubungqina bubonisa ukuba inokugcinwa emva kokungasebenzi kwe-VTA (Corbit et al., 2007) kodwa, njengoko ICorbit kunye neJanak (2007) kuxelwe mva nje, utshintshiselwano oluthile luphelisiwe ngokungasebenzi kwe-DLS, ecebisa ukuba lo mba wolawulo lovuselelo kukhetho lwesenzo unokubandakanya uqikelelo lwe-nigrostriatal (Corbit kunye noJanak, ngo-2007). Ukuvumelana nembono yoluhlu lwemigangatho, ICorbit kunye neJanak (2007) Kwakhona kwafumanisa ukuba, ngelixa ukungasebenzi kwe-DLS kuphelise isiphumo esikhethiweyo sokuvusa i-palovian cues (kakhulu njengoko kuye kwabonwa emva kokulimala kweqokobhe le-accumbens UCorbit et al, ngo-2001), ukungasebenzi kwe-DMS kupheliswe kuphela isiphumo-ukukhethwa kokudluliselwa ngelixa kubonakala kugcinwe umphumo oqhelekileyo wokuxhamla kwezi mpawu, umkhwa obuye wabonwa emva kwezilonda ze-thalamus ephakathi, eyinxalenye ye-associative cortico-basal ganglia network (I-Ostlund kunye neBalleine, 2008). Ngokusekelwe kwezi ziphumo zokuqala, i-DMS ibonakala idibanisa kuphela ukudluliselwa okuthe ngqo, ngelixa i-DLS ingaba yimfuneko kuzo zombini iziphumo ezicacileyo kunye neziqhelekileyo zokuzonwabisa zePavlovian kwizenzo zezixhobo.

Okubangela umdla kukuba, iiprojekthi ze-limbic striatum ngokubanzi kwiiseli ze-DA eziphuhlisa i-dorsal striatum (Nauta et al., 1978; Nauta, ngo-1989); Uqikelelo lwe-dopaminergic kwi-striatum kunye noqikelelo lokuzala olubuyela kwi-midbrain luyi-asymmetrical kakhulu (Haber, 2003). I-limbic striatum ifumana igalelo elilinganiselweyo kwi-DA neurons ukanti ithumela imveliso ebanzi kwiseti enkulu ye-DA neurons, kwaye okwahlukileyo kuyinyani kwi-sensorimotor striatum. Ngaloo ndlela uthungelwano lwe-limbic lukwimeko efanelekileyo yokulawula i-associative kunye ne-sensorimotor networks. Apha i-neuroanatomy iyavumelana nedatha yokuziphatha ukuba ukuququzelelwa kwePavlovian yokuziphatha kwezixhobo kunamandla kakhulu kunomva; ngokwenene, ubungqina obuninzi bubonisa ukuba izenzo zezixhobo zivame ukuthintela, kunokuba zivuyise, i-Pavlovian CRs-ukufumanisa okusalindele inkcazo ye-neurobiological (UEllison noKonorski, ngo-1964; Williams, ngo-1965).

izigqibo

Imodeli ye-hierarchical exutyushwa apha, kufuneka iqatshelwe, yahluke kakhulu kwabanye abaxhomekeke ngokukodwa kwi-cortex kunye noqhagamshelwano olude phakathi kweendawo ze-cortical (I-Fuster, 1995). Ibandakanya amacandelo awaziwayo kunye nokudibanisa kwengqondo, kunokuba ijonge njenge-potpourri yeemodyuli ze-cortical, ngendlela ethile engachazwanga, izalisekisa uluhlu olubanzi lwemisebenzi yokuqonda. Ikwanqanda ukucinga, okuzuzwe njengelifa ukusuka kwi-19^th i-neurology yenkulungwane, ukuba i-cerebral cortex ngokubanzi, kunye ne-prefrontal cortex ngokukodwa, ngandlela-thile yenza iyunithi ye-homuncular 'ephezulu' elawula yonke ingqondo. (UMiller noCohen, ngo-2001).

Ngaphaya koko, uqikelelo oluninzi oluthe ngqo lunokufunyanwa kwimodeli yangoku: (i) Kufuneka kubekho iimpazamo zokuqikelela okwahlukileyo kwizenzo eziveliswe ngokwazo kunye neemeko/izivuseleli ezineepropati ezibonisa ii-neural substrates zazo ezahlukeneyo kunye neendima ezisebenzayo. (ii) Amacandelo e-pallidal kunye ne-thalamic ye-discrete cortico-basal ganglia network nayo ilindeleke ukuba ibe yimfuneko kuhlobo lolawulo lokuziphatha oluqikelelwayo kuthungelwano ngalunye, kungekhona nje i-cortical kunye ne-striatal components. (iii) Kufuneka kubekho uthatho-nxaxheba oluqhubela phambili lothungelwano lwemithambo-luvo olwahlukeneyo ngamaxesha ahlukeneyo okufunda. (iv) Umsebenzi we-Accumbens unokulawula ngokuthe ngqo i-neurons ye-DA kwaye, emva koko, umsebenzi we-dorsal striatal. Ngokusekelwe kwingxelo ka eHolland (2004) icebisa ukuba i-PIT yonyuka ngoqeqesho lwezixhobo, olu lawulo 'lwe-limbic' lwe-associative kunye nothungelwano lwe-sensorimotor kulindeleke ukuba lomelele ngoqeqesho olwandisiweyo.

Ngaphandle kwedatha eneenkcukacha, kuse early kakhulu ukunika ingxelo esesikweni yemodeli yehierarchical. Nangona kunjalo, le ngxoxo ingentla kufuneka icacise ukuba iinguqulelo zangoku ze-mesoaccumbens umvuzo we-hypothesis ziphumle kwiingcamango eziyingxaki malunga nobume benkqubo yomvuzo kunye nokusetyenziswa kwemilinganiselo yokuziphatha engafanelekanga. Imithetho-siseko emanyanisayo, esoloko iyinjongo yeshishini lezenzululwazi, inokusekwa kuphela kubunyani bedatha yovavanyo, nangona oku kungalawuleki. Ngenxa yokuba umsebenzi wengqondo, ekugqibeleni, isizukulwana kunye nokulawulwa kokuziphatha, uhlalutyo olucacileyo lokuziphatha luya kuba sisitshixo sokuqonda iinkqubo ze-neural, njengoko inkcazo ecacileyo yokugonywa okungaphakathi kunye nokufunyenweyo kuvumela ukucaciswa kwe-immune system. Nangona kubonakala ngathi yinyani, ayinakugxininiswa kakhulu into yokuba sinokuziqonda iindlela zobuchopho ukusa kwinqanaba lokuba imisebenzi yazo ichazwe kwaye ilinganiswe ngokuchanekileyo. Xa uphononongo lomsebenzi we-neural lusekwe kubuchule bengqondo obusekiweyo, umzekelo ukumelwa kwesiphumo sentshukumo kunye nesiphumo sovuselelo, umbutho owaziwayo we-anatomical kunye neendlela ze-physiological zibonwa ngokukhanya okutsha, okukhokelela ekuqulunqweni kwezinto ezintsha. Uqikelelo kunye noyilo lwemifuniselo emitsha. Njengenyathelo lokuqala kweli cala, sinethemba lokuba inkqubo-sikhokelo exoxwa apha iya kusebenza njengesiqalo esiluncedo kuphando lwexesha elizayo.

Imibulelo

Ucaphulo