Effects of GABA and diazepam on 3H-serotonin release from hippocampal synaptosomes

Eur J Pharmacol. 1980 Nov 7;68(1):11-6. doi: 10.1016/0014-2999(80)90054-0.


The effects of GABA and diazepam on the spontaneous and potassium-evoked release of 3H-5-HT from rat hippocampal synaptosomes, preloaded by incubation with 3H-5-HT, have been investigated. Both GABA and diazepam independently increased the spontaneous release of 5-HT whereas they blocked the calcium-dependent, potassium-evoked release. However diazepam antagonised the GABA-mediated increase in spontaneous release but enhanced the inhibitory effects of GABA on potassium-stimulated release. The results suggest that 5-HT release in the hippocampus is under the presynaptic control of GABA and that diazepam may selectively enhance the inhibitory effect of GABA on the evoked release of 5-HT.

MeSH terms

  • Animals
  • Diazepam / pharmacology*
  • Hippocampus / drug effects*
  • Hippocampus / metabolism
  • In Vitro Techniques
  • Male
  • Rats
  • Serotonin / metabolism*
  • Synaptosomes / drug effects*
  • Synaptosomes / metabolism
  • gamma-Aminobutyric Acid / pharmacology*


  • Serotonin
  • gamma-Aminobutyric Acid
  • Diazepam