Selectivity of the spatial learning deficit after lesions of the mammillary region in rats.
Rats with lesions of the mammillary region (MB-R) or a control group (C) were trained on a visual-spatial conditional associative learning task in which they had to learn to go to one of two locations depending on the particular visual cue presented on each trial; the rats approached the cues from different directions. The animals were subsequently tested on a spatial working memory task, the eight-arm radial maze. Rats with damage to the MB-R were able to acquire the conditional associative task at a rate comparable to that of the C animals. By contrast, lesions of the MB-R led to a severe impairment on the radial maze. The present finding of a dissociation between the effects of MB-R lesions on two different classes of behavior suggest that the spatial learning deficit following damage of this region may be specific to remembering one or more places over a given time but not the ability to form associations between visual and spatial stimuli.
Sziklas
V
V
Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada. viv@ego.psych.mcgill.ca
Petrides
M
M
D000818:Animals; D001245:Association Learning / Q000502:physiology*; D001931:Brain Mapping; D003213:Conditioning, Psychological; D008326:Mammillary Bodies / Q000502:physiology*; D018782:Maze Learning / Q000502:physiology*; D008568:Memory / Q000502:physiology; D051381:Rats; D013028:Space Perception / Q000502:physiology*