Anterograde and Retrograde Amnesia of Place Discrimination in Retrosplenial Cortex and Hippocampal Lesioned Rats

• Published in: Learning & memory (Cold Spring Harbor, N.Y.) Vol. 15; no. 7; pp. 477 - 482
• Main Authors: Haijima, Asahi, Ichitani, Yukio
• Format: Journal Article
• Language: English
• Published: Cold Spring Harbor, NY Cold Spring Harbor Laboratory Press 01.07.2008
• Subjects: Amnesia, Anterograde - physiopathology; Amnesia, Retrograde - physiopathology; Analysis of Variance; Animals; Behavior, Animal; Behavioral psychophysiology; Biological and medical sciences; Brain Hemisphere Functions; Control Groups; Discrimination Learning - physiology; Disease Models, Animal; Disorders of higher nervous function. Focal brain diseases. Central vestibular syndrome and deafness. Brain stem syndromes; Entorhinal Cortex - injuries; Entorhinal Cortex - physiopathology; Fundamental and applied biological sciences. Psychology; Hippocampus - injuries; Hippocampus - physiopathology; Intervals; Male; Maze Learning - physiology; Medical sciences; Memory; Nervous system (semeiology, syndromes); Neurological Impairments; Neurology; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Rats; Rats, Wistar; Retention (Psychology); Retention (Psychology) - physiology; Spatial Ability; Surgery; Task Analysis; Time Factors; Memory disorder; Nervous system diseases; Cognitive disorder; Retrograde amnesia; Rat; Anterograde amnesia; Rodentia; Central nervous system; Encephalon; Cerebral disorder; Vertebrata; Mammalia; Discrimination; Animal; Central nervous system disease; Lesion; Neurological disorder; Hippocampus
• ISSN: 1072-0502; 1549-5485
• DOI: 10.1101/lm.862308

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.