Evidence for a depressive-like state induced by repeated saline injections in Fischer 344 rats

Pharmacol Biochem Behav. 1997 Aug;57(4):883-8. doi: 10.1016/s0091-3057(96)00455-8.

Abstract

We investigated the behavioral changes induced by mild stress in animals that may be relatively susceptible to a depressive-like state, the Fischer 344 rat strain. The mild stress of repeated handling and intraperitoneal (i.p.) injections with saline (2 ml/kg, twice a day for 14 days) elicited a moderate suppression of body weight gain, a decrease in open field activity, and a prolonged immobility during the tail suspension test in Fischer 344 rats compared with Sprague-Dawley rats. Chronic treatment of Fischer 344 rats with imipramine (10 mg/kg i.p., twice a day for 14 days) effectively suppressed open field activity and prolonged immobility. These results suggest that repeated saline injections may be a mild stressor in these rats. In the Fischer 344 strain, which may be vulnerable to the effects of mild stressors, repeated saline injections might induce a depressive-like state and could presumably represent an experimental model for depression.

Publication types

  • Comparative Study

MeSH terms

  • Animals
  • Antidepressive Agents, Tricyclic / pharmacology
  • Body Weight
  • Depressive Disorder / chemically induced*
  • Depressive Disorder / physiopathology
  • Depressive Disorder / psychology
  • Emotions / physiology
  • Handling, Psychological
  • Hindlimb Suspension
  • Imipramine / pharmacology
  • Male
  • Motor Activity / physiology
  • Rats
  • Rats, Inbred F344
  • Rats, Sprague-Dawley
  • Sodium Chloride / toxicity*

Substances

  • Antidepressive Agents, Tricyclic
  • Sodium Chloride
  • Imipramine