Learning impairment induced by lesion of the CA1 field of the primate hippocampus: attempts to ameliorate the impairment by transplantation of fetal CA1 tissue.

摘要: Monkeys with bilateral excitotoxic lesion of the CA1 field hippocampus were severely impaired at learning visuospatial conditional tasks. This was not a general spatial impairment, because animals on serial reversal, which requires response flexibility in domain; they to choose position furthest away from single stimulus, analysis layout test area, and discriminating between two patterns that differed only orientation. CA1-lesioned monkeys task when trials component types ”if AA go left” BB right” presented according either pseudorandom or alternating schedule; but if one type trial until three consecutive correct responses made, followed by other trial, responses. In all cases testing continued criterion 27 30 across both achieved. Although this suggests are particularly prone interference effects, had no difficulty ten concurrent visual discriminations against uniform background each discrimination its own distinctive background, condition might reduce unoperated monkeys. Interference following hippocampal damage occur deeper level than stimulus identification such may be able learn about many aspects different stimuli parallel unable multiple related same subject matter. grafts fetal tissue lesioned showed significant improvement relative those tasks impaired, although remained control animals. produced some performance. Grafted did differ sensitive damage. demonstrates have an additional deleterious effect cognitive