Effect of oxiracetam and piracetam on central cholinergic mechanisms and active-avoidance acquisition

Clin Neuropharmacol. 1986;9 Suppl 3:S39-47.

Abstract

Oxiracetam at 100 and 300 mg/kg i.p. dose levels increased acetylcholine (ACh) utilization in the rat cerebral cortex and hippocampus. ACh utilization was assessed by measuring, with a gas chromatographic method, the decrease in ACh level after inhibiting its synthesis by 15 micrograms intracerebroventricularly (i.c.v.) injection of hemicholinium (HC-3). ACh steady state levels were not affected. Piracetam (300 mg/kg i.p.) also increased ACh utilization in the hippocampus. Repeated daily administration of oxiracetam 100 mg/kg i.p. caused a 31% increase in high-affinity choline uptake (HACU) in the hippocampus. A single administration of 300 mg/kg i.p. of oxiracetam and piracetam also increased HACU rate in the hippocampus. However, the effect of piracetam was over within 3 h, while 3 h after its administration oxiracetam still caused a 40% increase in HACU rate. Oxiracetam (100 mg/kg i.p.) significantly antagonized the impairment in the acquisition of an active-avoidance conditioned response (pole climbing) associated with the inhibition of ACh synthesis by HC-3. These results indicate that oxiracetam enhances the activity of the septohippocampal cholinergic pathways, and to a lesser extent, of the cortical cholinergic network.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylcholine / metabolism*
  • Animals
  • Avoidance Learning / drug effects*
  • Brain Chemistry / drug effects*
  • Cerebral Cortex / metabolism
  • Choline / metabolism
  • Corpus Striatum / metabolism
  • Hemicholinium 3 / pharmacology
  • Hippocampus / metabolism
  • Male
  • Piracetam / pharmacology*
  • Pyrrolidines / pharmacology*
  • Pyrrolidinones / pharmacology*
  • Rats
  • Rats, Inbred Strains

Substances

  • Pyrrolidines
  • Pyrrolidinones
  • Hemicholinium 3
  • Choline
  • Acetylcholine
  • oxiracetam
  • Piracetam