Stimulation of hippocampal 5-HT1A receptors causes amnesia and anxiolytic-like but not antidepressant-like effects in the rat

Eur J Pharmacol. 1993 Apr 6;234(2-3):215-21. doi: 10.1016/0014-2999(93)90956-i.


Administration of 2 and 5 but not 0.4 microgram/microliter 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) into the CA1 region of the dorsal hippocampus 10 min before the acquisition trial in a passive avoidance task significantly reduced retention latencies 24 h later. The effect of 5 micrograms 8-OH-DPAT on retention latencies was completely antagonized by 1 microgram/microliter spiroxatrine, a 5-HT1A receptor antagonist, infused into the dorsal hippocampus 5 min before 8-OH-DPAT. Administered 5 min after the acquisition trial, 5 micrograms/microliters 8-OH-DPAT had no effect on retention latencies 24 h later. Administration of 5 micrograms/microliters 8-OH-DPAT into the dorsal hippocampus did not significantly change the thresholds for responses to the same electrical stimuli used in the passive avoidance task and had no antidepressant-like effect in the forced swimming test. The dose of 5 micrograms/microliters 8-OH-DPAT administered into the dorsal hippocampus caused anxiolytic-like effects assessed by stress-induced deficit in open field locomotor activity. The results suggest that stimulation of 5-HT1A receptors in the dorsal hippocampus impairs rats' performance in a passive avoidance task by interfering with memory processes or by attenuating the emotional impact of the shock through an anxiolytic action.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 8-Hydroxy-2-(di-n-propylamino)tetralin / pharmacology*
  • Amnesia / chemically induced*
  • Animals
  • Anti-Anxiety Agents / pharmacology*
  • Antidepressive Agents / pharmacology*
  • Avoidance Learning / drug effects
  • Emotions / drug effects
  • Hippocampus / anatomy & histology
  • Hippocampus / drug effects*
  • Injections
  • Male
  • Motor Activity / drug effects
  • Nociceptors / drug effects
  • Pain Threshold / drug effects
  • Rats
  • Receptors, Serotonin / drug effects*
  • Serotonin Receptor Agonists / pharmacology
  • Swimming


  • Anti-Anxiety Agents
  • Antidepressive Agents
  • Receptors, Serotonin
  • Serotonin Receptor Agonists
  • 8-Hydroxy-2-(di-n-propylamino)tetralin