?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.title=Dopaminergic+agonistic+and+antagonistic+drugs+in+the+ventral+tegmentum+of+rats+inhibit+and+facilitate+changes+of+food-search+behaviour&rft.creator=Oades%2C+&rft.subject=Behavioral+Neuroscience&rft.subject=Behavioral+Biology&rft.subject=Neuropharmacology&rft.subject=Psychobiology&rft.description=Introduction%3A+%0AThe+proposal+that+an+increase+of+dopaminergic+(DA)+activity+in+the+mesocorticolimbic+pathway+with+an+origin+in+the+ventral+tegmental+area+(VTA+A10)+increases+the+probability+of+behavioural+change+was+tested+(Koob+et+al.%2C+1978+-+see+also+Oades%2C+1985+on+the+switching+role+of+DA)%0A%0AMethods%3A%0AFood-deprived+animals+searched+for+food+pellets+placed+consistently+in+4+holes+of+a+16-hole-board.+They+were+presented+with+9+sessions+of+10+trials%2Fsession.+Groups+of+rats+received+lesions+of+the+VTA+or+injections+of+the+DA+D2+antagonist+spiroperidol+(2%C2%B5g%2F0.5+%C2%B5l)+or+the+DA+agonist+apomorphine+(2+%C2%B5g(0.5%C2%B5l)+into+the+VTA+before+sessions+4+and+7.%0A%5BNeuroleptic+treatment+should+block+local+inhibition+via+autoreceptors+and+thus+lead+to+increased+DA+activity+in+the+terminal+regions%5D%0A%0AResults%3A+%0A1%2F+Compared+to+vehicle-+or+apomorphine-treatment%2C+spiroperidol+increased+the+number+of+empty+hole-visits+(errors)%0A2%2F+Comparison+animals+(vehicle-+and+apomorphine+treated)+developed+individually+specific+but+consistent+sequences+of+hole-visits+(%22strategy%22)+--+these+were+disrupted+on+sessions+4+and+7+after+neuroleptic+treatment+and+following+VTA+damage.%0A(i.e.+there+was+much+intra-session+switching+between+sequences+from+trial+to+trial.)%0A3%2F+Further+the+identity+of+the+preferred+sequence+on+session+7+was+more+often+different+than+on+session+4+for+lesioned+and+neuroleptic+treated+animals+than+for+the+comparison+groups.%0A(i.e+there+was+also+inter-session+switching+between+sequences+between+sessions+4+and+7.)%0A4%2F+Although+many+apomorphine-treated+animals+changed+their+preference+on+session+4%2C+this+was+not+repeated+after+the+second+treatment+on+session+7+-+when+fewer+changes+were+recorded+than+for+the+controls..+%0A%0AConclusions%3A%0A.The+results+are+consistent+with+increased+switching+of+strategies+in+animals+with+increased+mesocorticolimbic+DA+activity+-+where+the+learning+and+maintenance+of+strategies+are+seen+as+an+aid+to+recall+the+adaptive+sequence+of+behaviour+likely+to+lead+to+the+relevant+baited+holes.%0A&rft.publisher=Elsevier&rft.date=1981&rft.type=Journal+(Paginated)&rft.type=PeerReviewed&rft.format=application%2Fpdf&rft.identifier=http%3A%2F%2Fcogprints.org%2F1481%2F2%2Frat-nsci-lett-81.pdf&rft.identifier=++Oades%2C+++(1981)+Dopaminergic+agonistic+and+antagonistic+drugs+in+the+ventral+tegmentum+of+rats+inhibit+and+facilitate+changes+of+food-search+behaviour.++%5BJournal+(Paginated)%5D+++++&rft.relation=http%3A%2F%2Fcogprints.org%2F1481%2F