Effects of oxiracetam on neurotransmitter release from rat hippocampus slices and synaptosomes

Neurosci Lett. 1992 Sep 28;145(1):109-13. doi: 10.1016/0304-3940(92)90215-s.


The effects of the nootropic drug oxiracetam on the K(+)-evoked overflow of [3H]D-aspartic acid ([3H]D-ASP), [3H]acetylcholine ([3H]ACh), [3H] gamma-aminobutyric acid ([3H]GABA), [3H]noradrenaline ([3H]NA) and [3H]5-hydroxytryptamine ([3H]5-HT) have been studied in superfused rat hippocampal slices. The overflow of [3H]D-ASP was enhanced by low concentrations of oxiracetam (0.01-1 microM) but not by high concentrations (10-100 microM) which showed some tendency to inhibit it. Similarly, low concentrations of oxiracetam increased, although less effectively, the depolarization-evoked overflow of [3H]ACh, whereas higher concentrations were without effect. At the concentrations active on [3H]D-ASP and [3H]ACh overflow oxiracetam did not affect that of [3H]GABA, [3H]NA or [3H]5-HT. The oxiracetam effects present in slices could not be observed in hippocampal synaptosomes. Thus oxiracetam may selectively increase the release of glutamate and acetylcholine in hippocampus by a mechanism which appears not to be sited in the releasing nerve terminals.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylcholine / metabolism
  • Animals
  • Aspartic Acid / metabolism
  • Hippocampus / drug effects
  • Hippocampus / metabolism*
  • In Vitro Techniques
  • Male
  • Nerve Endings / drug effects
  • Nerve Endings / metabolism
  • Neurotransmitter Agents / metabolism*
  • Norepinephrine / metabolism
  • Potassium / pharmacology
  • Psychotropic Drugs / pharmacology*
  • Pyrrolidines / pharmacology*
  • Rats
  • Rats, Sprague-Dawley
  • Serotonin / metabolism
  • Synaptosomes / drug effects
  • Synaptosomes / metabolism*
  • gamma-Aminobutyric Acid / metabolism


  • Neurotransmitter Agents
  • Psychotropic Drugs
  • Pyrrolidines
  • Aspartic Acid
  • Serotonin
  • gamma-Aminobutyric Acid
  • Acetylcholine
  • oxiracetam
  • Potassium
  • Norepinephrine