J Neurosci. 2016 Jan 6;36(1):235-50. doi: 10.1523/JNEUROSCI.3468-15.2016.
Saddoris MP1, Wang X2, I-Sugam JA2, Carelli RM2.
Abstract
Ukubonakaliswa okungapheliyo kwiziyobisi zokuxhatshazwa kudibaniswa nokuguqulwa kwexesha elide kumsebenzi wezakhiwo ze-limbic system, kuquka i-nucleus accumbens (NAc). Nangona i-cocaine isebenza ngeendlela ze-dopaminergic ngaphakathi kwe-NAc, kuncinci okwaziwayo malunga nokuba i-phasic dopamine (DA) yokusayina kwi-NAc iyatshintshwa kwizilwanyana ezinamava okuzilawula kwe-cocaine okanye ukuba ezi zilwanyana zifunda kwaye zinxibelelane ngokwesiqhelo kunye nezivuseleli kwindawo yazo. Apha, amaqela ahlukeneyo eempuku azinikezela ngokwawo nokuba yi-cocaine ye-intravenous okanye amanzi kwi-receptacle (ulawulo), elandelwa yi-30 d yokunyanzelwa ukuyeka. Emva koko, zonke iimpuku zafunda ucalucalulo lwePavlovian kunye nokurekhodwa kwevoltammetric yokukhutshwa kwexesha lokwenyani le-DA kuthathwe nokuba kungundoqo we-NAc okanye igobolondo le-cocaine kunye nezifundo zolawulo. Amava e-Cocaine ngokwahlukileyo onakalise ukubonakaliswa kwe-DA kumbindi kunye neqokobhe elinxulumene nolawulo. Nangona imiqondiso ye-DA ye-phasic kwiqokobhe iye yapheliswa ngokuyimfuneko kuzo zonke izivuseleli, eyona nto iphambili, i-DA ayizange yahlule phakathi kwee-cues kwaye yayithambekele ngokungaqhelekanga kunikezelo lomvuzo. Ngaphaya koko, iimpuku ze-cocaine azikwazanga ukufunda imibutho enomgangatho ophezulu kunye nokutshintsha iindlela zokuziphatha ezilula, ezibonisa ukuzixakekisa okuyanyaniswa ne-cue-eyayanyaniswa ne-cue-tracking; ST) kodwa ixesha elinciphileyo kwindebe yokutya elindele ukuhanjiswa komvuzo (ukulandela umkhondo) . Ngokucacileyo, ngelixa ulawulo lokusayinwa kwe-DA lunxibelelene nokuziphatha kwe-ST, amava e-cocaine aphelisa obu budlelwane. Ezi ziphumo zibonisa ukuba i-cocaine inezingiso, umahluko, kunye neziphumo ze-pathological kuzo zombini ukubonakaliswa kwe-DA kunye nokuziphatha okuxhomekeke kwi-DA kwaye icebisa ukuba amava e-psychostimulant anokulungisa ezona ziphaluka ezithi zithande ukuphinda ziphinde zibuyele.
INDLELA YOKUZIPHATHA UMYALEZO:
Ukubuyela ekusetyenzisweni kakubi kweziyobisi nangona ukhe waziyeka yaye uzama ngokunyanisekileyo ukuyeka le yenye yezona nkalo ziyingozi zokukhotyokiswa. Ngelishwa, kuncinci okwaziwayo malunga nendlela esebenza ngayo inkqubo ye-dopamine (DA) emva kwamaxesha okuyeka iziyobisi, ngakumbi indima yayo ekuziphatheni kwiimeko ezingezizo iziyobisi. Apha, iimpuku zafunda malunga nokukhuthaza ukutya okuphekiweyo emva kokuyeka ixesha elide kulawulo lwe-cocaine. Sisebenzisa ivoltammetry, sifumanise ukuba imiqondiso ye-DA yexesha lokwenyani kwiimpuku ezinamava e-cocaine zatshintshwa ngokumangalisayo xa kuthelekiswa nolawulo. Ngaphaya koko, izilwanyana ezinamava e-cocaine zifumene isivuseleli esilindele umvuzo ngokungaqhelekanga kwaye sichithe ixesha elingakumbi sinxibelelana neempawu. Ke ngoko, i-cocaine idala utshintsho lwe-neuroplastic kwinkqubo ye-DA etyekela izilwanyana kwi-stimuli esebenzayo (kubandakanywa neempawu ezinxulumene nomvuzo), ibeka abakhotyokiyo emngciphekweni owandayo wokuphinda babuyele njengoko umlutha wonyuka ngobunzima.
IINKCUKACHA:
Ukunyaniseka kwenkuthazo; impazamo yoqikelelo; uphawu lokulandelela; i-ventral striatum; ivoltametry
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