Showing papers by "Trevor W. Robbins published in 1977"

The effects of isolation rearing on exploration in the rat

Abstract: The hypothesis that isolation rearing enhances exploration was tested in two settings which varied the extent to which exploratory behavior would be affected by competing hyperactivity. Experiment 1 measured exploration as contact of a discrete novel stimulus, in terms of bout frequency and duration. Locomotor activity was measured by photocell beam interruption. Isolation-reared rats were hyperactive, showed an increased incidence of exploratory bouts but no differences in duration of exploratory behavior, compared with group-reared controls. Experiment 2 measured, independently, locomotor activity and the preference for a novel environment over a familiar one. Isolation-reared rats, whether male or female, showed enhanced novelty preference compared with controls. No significant differences were found in locomotor activity. The results are discussed in terms of the hyperactivity of isolates interfering with investigative behavior by response incompatibility.

Effects of chlordiazepoxide on tail pinch-induced eating in rats.

Abstract: The effects of 5, 10, and 20 mg/kg chlordiazepoxide on tail pinch (TP)-induced behavior were investigated. Five mg/kg enhanced TP-induced eating in terms of both latency and duration. Twenty mg/kg had decremental effects. All doses of the drug reduced the incidence of clip-directed behavior, but increased locomotor activity during the TP trials in a dose-dependent manner. On control trials, the drug increased locomotor activity at the low dose and eating at the high dose. The results are examined in terms of the various behavioral actions of the minor tranquilizers. The implications for the behavioral and neuropharmacological mechanisms underlying TP-induced and other forms of stimulus-bound behavior are discussed.