Lesions of the rat postsubiculum impair performance on spatial tasks.
Previous studies have identified a population of neurons in the postsubiculum that discharge as a function of the rat's head direction in the horizontal plane (Taube, Muller, & Ranck, 1990a). To assess the contribution of these cells in spatial learning, Long-Evans rats were tested in a variety of spatial and nonspatial tasks following bilateral electrolytic or neurotoxic lesions of the postsubiculum. Compared to unlesioned control animals, lesioned animals were impaired on two spatial tasks, a radial eight-arm maze task and a Morris water task, although the performance scores of both lesion groups improved over the course of behavioral testing. In contrast, lesioned animals were unimpaired on two nonspatial tasks, a cued version of the water maze task and a conditioned taste-aversion paradigm. In addition, lesioned animals showed transient hyperactivity in an open-field activity test. These results support the concept that neurons in the postsubiculum are part of a neural network involved in the processing of spatial information.
Taube
J S
JS
Department of Psychobiology, University of California, Irvine 92717.
Kesslak
J P
JP
Cotman
C W
CW
D000818:Animals; D001362:Avoidance Learning / Q000502:physiology; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000502:physiology*; D003214:Conditioning, Classical / Q000502:physiology; D004193:Discrimination Learning / Q000502:physiology; D004924:Escape Reaction / Q000502:physiology; D005239:Fear / Q000502:physiology; D006624:Hippocampus / Q000502:physiology*; D008297:Male; D011939:Mental Recall / Q000502:physiology*; D009043:Motor Activity / Q000502:physiology; D009434:Neural Pathways / Q000502:physiology; D009474:Neurons / Q000502:physiology; D009949:Orientation / Q000502:physiology*; D051381:Rats; D012153:Retention, Psychology / Q000502:physiology*; D012931:Social Environment; D013649:Taste / Q000502:physiology