title: Anterograde and retrograde amnesia of place discrimination in retrosplenial cortex and hippocampal lesioned rats.
abstract: Retrograde and anterograde amnesic effects of excitotoxic lesions of the rat retrosplenial cortex (RS) and hippocampus (HPC) were investigated. To test retrograde amnesia, rats were trained with two-arm place discrimination in a radial maze 4 wk and 1 d before surgery with a different arm pair, respectively. In the retention test 1 wk after surgery, both lesion groups showed temporally ungraded retrograde amnesia. To test anterograde amnesia, animals were trained after surgery to discriminate three arm pairs successively within a day, and then after interposition of 1- to 4-wk intervals, one of these pairs, respectively, was tested for retention. RS-lesioned rats could acquire these pairs of place discriminations rapidly but showed a retention interval-dependent impairment in the retention test. Conversely, HPC-lesioned rats took more sessions to acquire these pairs than did the control group, and their retention was approximately 70% of correct performance regardless of retention interval. Results suggest that RS and HPC have different roles in spatial memory and that RS is important for remote memory process.
authors.affiliation: Institute of Psychology and Behavioral Neuroscience, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan.
authors.forename: Asahi
authors.initials: A
authors.lastname: Haijima
authors.forename: Yukio
authors.initials: Y
authors.lastname: Ichitani
mesh_terms: D020324:Amnesia, Anterograde / Q000503:physiopathology*; D000648:Amnesia, Retrograde / Q000503:physiopathology*; D000704:Analysis of Variance; D000818:Animals; D001522:Behavior, Animal; D004193:Discrimination Learning / Q000502:physiology*; D004195:Disease Models, Animal; D018728:Entorhinal Cortex / Q000293:injuries* / Q000503:physiopathology; D006624:Hippocampus / Q000293:injuries* / Q000503:physiopathology; D008297:Male; D018782:Maze Learning / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D012153:Retention, Psychology / Q000502:physiology; D013997:Time Factors