Role of hippocampal 5-HT1A receptors on elevated plus maze exploration after a single restraint experience

Behav Brain Res. 1996 May;77(1-2):215-8. doi: 10.1016/0166-4328(95)00211-1.

Abstract

Previous studies have shown that 2 h restraint stress induces deficits in open arm exploration of an elevated plus maze 24 h later. This effect was attenuated by a post-stress systemic injection of the 5-HT non-selective agonist, 5-methoxy-N,N-dimethyltryptamine (5-MeODMT). To verify a possible involvement of hippocampal 5-HT1A receptors in this effect, rats were stereotaxically implanted with canulae in the dorsal hippocampus. Seven days later they received bilateral microinjections of 5-MeODMT (20 nmol/0.5 microliter) or saline. No difference was found on exploration of an elevated plus maze 24 h later. However, when treatments were performed immediately after 2 h of restraint stress, the drug was able to increase open arm exploration 24 h later. This effect was antagonized by a previous microinjection of (+)WAY-100135 (40 nmol/0.5 microliter), a selective 5-HT1A antagonist. The results suggest that hippocampal 5-HT1A receptors may attenuate stress behavioral consequences.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Arousal / drug effects
  • Arousal / physiology*
  • Brain Mapping
  • Exploratory Behavior / drug effects
  • Exploratory Behavior / physiology*
  • Hippocampus / drug effects
  • Hippocampus / physiology*
  • Male
  • Maze Learning / drug effects
  • Maze Learning / physiology*
  • Mental Recall / drug effects
  • Mental Recall / physiology*
  • Methoxydimethyltryptamines / pharmacology
  • Piperazines / pharmacology
  • Rats
  • Rats, Wistar
  • Receptors, Serotonin / drug effects
  • Receptors, Serotonin / physiology*
  • Restraint, Physical
  • Serotonin Antagonists / pharmacology
  • Serotonin Receptor Agonists / pharmacology

Substances

  • Methoxydimethyltryptamines
  • Piperazines
  • Receptors, Serotonin
  • Serotonin Antagonists
  • Serotonin Receptor Agonists
  • WAY 100135