کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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6265798 | 1614224 | 2008 | 10 صفحه PDF | دانلود رایگان |
Sprague Dawley rats were submitted to bilateral ventral hippocampus lesions 7Â days after birth. This corresponds to the Lipska and Weinberger's procedure for modeling schizophrenia. The aim of the present work was to test the learning capacity of such rats with an associative Pavlovian and an instrumental learning paradigm, both methods using reward outcome (food, sucrose or polycose). The associative paradigm comprised also a second learning test with reversed learning contingencies. The instrumental conditioning comprised an extinction test under outcome devaluation conditions. Neonatally lesioned rats, once adults (over 60Â days of age), showed a conditioning deficit in the associative paradigm but not in the instrumental one. Lesioned rats remained able to adapt as readily as controls to the reversed learning contingency and were as sensitive as controls to the devaluation of outcome. Such observations indicate that the active access (instrumental learning) to a reward could have compensated for the deficit observed under the “passive” stimulus-reward associative learning condition. This feature is compared to the memory management impairments observed in clinical patients.
Journal: Brain Research - Volume 1215, 18 June 2008, Pages 190-199