Effects of discrete kainic acid-induced hippocampal lesions on spatial and contextual learning and memory in rats

• Published in: Brain research 1996-04, Vol.716 (1), p.29-38
• Main Authors: Stubley-Weatherly, LeighAnn, Harding, Joseph W., Wright, John W.
• Format: Article
• Language: English
• Subjects: Anatomical correlates of behavior; Animals; Avoidance Learning - drug effects; Behavior, Animal - drug effects; Behavioral psychophysiology; Biological and medical sciences; CA1; CA3; Excitatory Amino Acid Agonists - toxicity; Fundamental and applied biological sciences. Psychology; Hippocampus; Hippocampus - drug effects; Hippocampus - pathology; Hippocampus - physiology; Kainic acid; Kainic Acid - toxicity; Learning - drug effects; Male; Maze Learning - drug effects; Memory; Memory - drug effects; Orientation - drug effects; Passive avoidance; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Rats; Rats, Sprague-Dawley; Reversal Learning - drug effects; Space Perception - drug effects; Spatial learning; Swimming; Water maze
• ISSN: 0006-8993; 1872-6240
• DOI: 10.1016/0006-8993(95)01589-2

Substantial information is available concerning the influence of global hippocampal lesions on spatial learning and memory, however the contributions of discrete subregions within the hippocampus to these functions is less well understood. The present investigation utilized kainic acid to bilaterally lesion specific areas of the rat hippocampus. These animals were subsequently tested on a spatial orientation task using a circular water maze, and on an associative/contextual task using passive avoidance conditioning. The results indicate that both the dorsal CA1 and the ventral CA3 subregions play important roles in learning. Specifically, CA1 lesions produced a deficit in the acquisition of the water maze task and a significant memory impairment on the passive avoidance task. CA3 lesions also caused learning deficits in the acquisition of the water maze task, and produced even greater impairments in performance on the passive avoidance task. We conclude that CA1 and CA3 hippocampal subregions each play significant roles in the overall integration of information concerning spatial and associative learning.