Does a single exposure to social defeat render rats more vulnerable to chemically induced colitis than brief inescapable foot-shocks?

PLoS One. 2022 Aug 24;17(8):e0263802. doi: 10.1371/journal.pone.0263802. eCollection 2022.

Abstract

All mammals are to different degrees exposed to stressors being physical or social, which may affect health and well-being. Stressful and traumatic situations have direct effects on immune responses that may alter susceptibility to developing somatic illnesses. In animal research, different types of stressors have been investigated in studying the effect on bowel disorders, some stressors being more or less of environmental origin. We aimed, therefore, to explore whether a more natural stressor would differ from a stressor of more unnatural characteristics on dextran sulphate sodium (DSS) induced colitis in adult rats. Specifically, whether social stress within a single social defeat (SD) paradigm would be a more potent stressor than brief inescapable foot-shocks (IFS) in causing elevated faecal granulocyte marker protein (GMP), and crypt- and inflammation scores in colonic tissue. Three groups of male Wistar rats were used; socially defeated rats; inescapable foot-shock rats; and comparison rats. Main findings showed no difference between the groups on GMP levels. However, there was a significant difference on inflammation and crypt scores for the distal part of colon, detected through histology, where socially defeated rats were more susceptible. A single SD seems to be more adverse than inescapable foot-shock on DSS induced colitis, but further studies are recommended to validate a broader range of different outcomes comparing two such different rodent stress models.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biomarkers
  • Colitis* / chemically induced
  • Dextran Sulfate / toxicity
  • Inflammation
  • Male
  • Mammals
  • Rats
  • Rats, Wistar
  • Social Defeat*
  • Stress, Psychological

Substances

  • Biomarkers
  • Dextran Sulfate

Grants and funding

This study was performed with support from the Faculty of Psychology, University of Bergen, Norway