The influence of brain damage on locomotor behavior of mice selectively bred for high or low activity in the open field.
Locomotor activity was measured in mice with lesions restricted to the neocortex, in animals with hippocampal damage, and in sham-operated control mice of the selectively bred high and low open-field activity lines developed by J. C. DeFries. Postoperatively, the high-activity animals with hippocampal lesions showed reduced activity relative to those with only neocortical damage, and their postoperative activity levels were uncorrelated with those obtained preoperatively. Testing the animals under reduced illumination enhanced locomotor activity, with the greatest increase demonstrated by high-activity mice with hippocampal damage. While increases in activity under low illumination did occur in the low-activity line, no significant group differences were observed. Amphetamine did not affect locomotor behavior of the high-activity control animals, whereas doses of 1.0 and 10.0 mg/kg reduced the activity of the low-activity mice. High-activity mice with hippocampal damage evidenced a significant increase in locomotor behavior after the 10.0 mg/kg dose. These results emphasize that the behavioral effects of brain lesions and pharmacological manipulations cannot be adequately assessed without regard to genotype of the animals under investigation.
D000661:Amphetamine / Q000494:pharmacology; D000818:Animals; D002540:Cerebral Cortex / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D005838:Genotype; D006624:Hippocampus / Q000502:physiology*; D051379:Mice; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology*; D012641:Selection, Genetic
D000661:Amphetamine