?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.title=Catecholamines+and+conditioned+blocking%3A+effects+of+ventral+tegmental%2C+septal+and+frontal+6-hydroxydopamine+lesions+in+rats&rft.creator=Oades%2C+R.D.&rft.creator=Rivet%2C+J-M.&rft.creator=Taghzouti%2C+K.&rft.creator=Kharouby%2C+M.&rft.creator=Simon%2C+H.&rft.creator=Le+Moal%2C+M.&rft.subject=Behavioral+Neuroscience&rft.subject=Animal+Cognition&rft.subject=Neuropharmacology&rft.subject=Psychobiology&rft.description=Introduction%3A+%0AThe+performance+of+rats+on+the+conditioned+blocking+test+(CB)+of+learned+inattention+was+measured+in+a+two-way+shuttle+avoidance+task+after+sham+and+dopamine+(DA)+-+depleting+lesions+of%0Athe+frontal+cortex%2C%0Athe+limbic+septum%2C+and%0Athe+ventral+tegmental+area+(VTA+-+A10).%0A%0AMethods%3A%0AAnimals+were+trained+on+two+sessions+with+tone+and+%2F+or+light+as+conditioned+stimuli.+One+group+was+trained+with+both+stimuli+on+both+sessions.+A+second+group+was+trained+on+the+first+session+with+one+stimulus+and+on+the+second+with+both+stimuli.+The+blocking+of+conditioning+to+the+added+stimulus+(b)+was+tested+by+presenting+the+stimuli+(a+and+b)+separately+and+measuring+the+blocking+ration+(avoidance+to+b%2Fa+%2B+b)+and+response+latencies.%0A%0AResults%3A+%0A1%2F+No+deficits+were+recorded+on+tests+of+sensory+and+motor+ability%3B%0A2%2F+The+VTA+group+alone+showed+a+hyperlocomotor+response+to+apomorphine+treatment%2C+-+and+did+not+acquire+the+avoidance+response+(i.e.+did+not+learn+the+active+avoidance+task)%3B%0A3%2F+The+appearance+of+blocking+in+the+septally+lesioned+group+was+delayed+until+the+end+of+the+20-trial+test+session+-+then+it+was+exaggerated%3B%0A4%2F+Blocking+was+mildly+attenuated+in+the+frontally+lesioned+group.%0A5%2F+Dopamine+(DA)+levels+were+depleted+by+about+80%25+and+noradrenaline+(NA)+levels+by%2C+respectively%2C+20%25+and+50%25+in+the+frontal+and+septal+regions.%0A%0AFigure+2+illustrates+a)+the+CB+impairment+in+the+frontal+group+relative+to+sham+controls%2C+and+b)+the+late+development+of+%22supr-blocking%22+in+septally-damage+animals.%0AFigure+3+illustrates+the+results+of+the+HPLC+analysis+for+NA%2C+DA+and+DOPAC+in+frontal+cortex%2C+septum%2C+N.+accumbens+and+striatum+after+6-OHDA+lesions+(%26+vehicle+treatment)+in+the+frontal%2C+septal%2C+and+VTA+areas.+%0A%0AConclusions%3A%0AThe+results+show+that+the+levels+of+DA+activity%2C+or+rather+the+balance+between+the+activity+of+DA+and+NA+in+frontal+and+limbic+regions+can+contribute+to+efficient+associative+conditioning+and+%2F+or+the+normal+ability+of+rats+not+to+attend+to+a+redundant+stimulus.%0A&rft.publisher=Elsevier&rft.date=1987&rft.type=Journal+(Paginated)&rft.type=PeerReviewed&rft.format=application%2Fpdf&rft.identifier=http%3A%2F%2Fcogprints.org%2F1371%2F2%2Fcb-rat-87.pdf&rft.identifier=++Oades%2C+R.D.+and+Rivet%2C+J-M.+and+Taghzouti%2C+K.+and+Kharouby%2C+M.+and+Simon%2C+H.+and+Le+Moal%2C+M.++(1987)+Catecholamines+and+conditioned+blocking%3A+effects+of+ventral+tegmental%2C+septal+and+frontal+6-hydroxydopamine+lesions+in+rats.++%5BJournal+(Paginated)%5D+++++&rft.relation=http%3A%2F%2Fcogprints.org%2F1371%2F