Selectivity of the spatial learning deficit after lesions of the mammillary region in rats

✍ Scribed by V. Sziklas; M. Petrides

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 320 KB
• Volume: 10
• Category: Article
• ISSN: 1050-9631
• DOI: 10.1002/1098-1063(2000)10:3<325::aid-hipo12>3.0.co;2-d

✦ Synopsis

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.