Analise dos efeitos de lesões hipocampais sobre a aprendizagem e memoria espacial de pombos em situação de escolha alimentar

AUTOR(ES)
DATA DE PUBLICAÇÃO

2003

RESUMO

Three groups of pigeons were studied: Hippocampal lesion, Sham lesion and No lesion. The first two experiments used a task of localization and choice between two food-cups in a rectangular transparent chamber. Experiments 3 and 4 sessions were run in a circular arena with choice among four food cups. Hippocampal lesion was carried out with ibotenic acid infusions both pre-training (Experiments 1 and 3) or post-training (Experiments 2 and 4). The pre and post-training, reversal and probe test sessions were video-recorded for quantification of the latency of choice and number of correct choices. The hippocampal groups showed significantly longer latencies of choice during post lesion tests and reversal sessions. The pre-training lesion affected the percent of correct choices only when the task favored spatial mapping strategy (Experiments 3 and 4). A retrieval test carried out 25 days after the end training (Experiment 4) indicated a large deficit in the retention of the long-term memory in lesioned pigeons. Finally, Experiments 5 and 6 evaluated the morphologic parameters of AgNOR in the hippocampus of pigeons submitted to the two spatial tasks. The training affected the size and relative area of AgNOR, with task-dependent differential effects both between hippocampal areas or hemispheres. These experiments corroborate previous studies with rodents and suggest functional similarity between the hippocampus of different animal species. The data also points to new evidence related to long-term spatial memory in hippocampal pigeons and to plastic changes subjacent to learning in different spatial tasks

ASSUNTO(S)

pombo hipocampo (cerebro) aprendizagem animal

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