Differential effects of social isolation upon body weight, food consumption, and responsiveness to novel and social environment in bombesin receptor subtype-3 (BRS-3) deficient mice

Physiol Behav. 2000 Feb;68(4):555-61. doi: 10.1016/s0031-9384(99)00214-0.


The effects of social isolation on body weight gain, food consumption, and responsiveness to novel and social environment were assessed in an animal model for obesity, bombesin receptor subtype-3 (BRS-3) deficient mice. In Experiment 1, body weight gain and food consumption of group- and isolation-housed wild-type and BRS-3-deficient mice were compared. In wild-type mice, group-housed animals showed greater mean body weight gain and food consumption than did the isolation-housed cohort in the early stage of the experiment, whereas in BRS-3-deficient mice, the isolation-housed mice showed greater body weight gain and food consumption than the group-housed cohort by prolonged isolation housing. In Experiment 2, isolation-housed wild-type mice exhibited increased stereotypic and vertical movements relative to group-housed subjects in a novel environment, but this effect was not observed in BRS-3-deficient mice. In Experiment 3, when social response was assessed in animals housed in isolation, BRS-3-deficient mice exhibited lower social responses than did wild-type mice. We conclude that BRS-3-deficient mice and wild-type mice are differentially affected by social isolation. These results suggest that BRS-3 expression in the CNS may affect the neural mechanisms that regulate isolation effects in wild-type animals.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aging / psychology
  • Animals
  • Behavior, Animal / physiology*
  • Body Weight / physiology*
  • Eating / physiology*
  • Female
  • Genotype
  • Male
  • Mice
  • Mice, Knockout
  • Motor Activity / physiology
  • Oxygen Consumption / physiology
  • Receptors, Bombesin / deficiency*
  • Receptors, Bombesin / genetics*
  • Social Environment*
  • Social Isolation / psychology*
  • Stereotyped Behavior / physiology
  • Weight Gain


  • Receptors, Bombesin
  • bombesin receptor subtype 3