Effect of stress on behaviour in rats.

The pattern of activity obtained in rats on a regimen of one hour access to food and water was compared to the activity pattern seen when immobilization stress was added to the same regimen. Food and water were provided at the same time of the day. Immobilization stress decreased the body weight, increased the time taken for grooming, maintaining at the same time the food intake. The water intake also increased significantly but the alcohol intake was variable, 3 of the rats showing an increased intake while the rest showed a decreased intake under this stress regimen. The pattern of activity changed from hyper-activity during food restriction alone to increased activity restricted to the first half of the testing time during added immobilization.