Intracerebroventricular injection of a nitric oxide synthase inhibitor does not affect long-term slope potentiation in vivo

David M Bannerman, S P Butcher, R G Morris

Research output: Contribution to journalArticlepeer-review

Abstract

Although there is evidence from in vitro studies to suggest that NO synthesis may be involved in the induction of hippocampal LTP, other in vitro studies and experiments conducted in vivo have provided conflicting results. In agreement with previous work conducted in this laboratory using an i.p. route of administration, this paper reports that i.c.v. injections of the NO synthase inhibitor, N omego-nitro-L-arginine methyl ester (L-NAME), at a dose sufficient to inhibit hippocampal NO synthase by 90-95%, failed to block the induction of LTP in the dentate gyrus in vivo (as measured by the change in the slope of the early rising phase of the field EPSP). The failure to block LTP occurred following both a strong and a weak tetanus. L-NAME injections did, however, result in a small but transient increase in the baseline slope of the field EPSP, a more prolonged enhancement of the baseline population spike, and a significant attenuation of spike potentiation induced by a strong tetanus. These results offer no support for the hypothesis that NO synthase is required for the induction of the synaptic component of LTP, but do suggest a role for NO in the control of cell excitability in the hippocampus.

Original languageEnglish
Pages (from-to)1387-97
Number of pages11
JournalNeuropharmacology
Volume33
Issue number11
Publication statusPublished - Nov 1994

Keywords

  • Amino Acid Oxidoreductases
  • Animals
  • Arginine
  • Electrophysiology
  • Evoked Potentials
  • Hippocampus
  • Injections, Intraventricular
  • Long-Term Potentiation
  • Male
  • NG-Nitroarginine Methyl Ester
  • Nitric Oxide
  • Nitric Oxide Synthase
  • Rats
  • Journal Article
  • Research Support, Non-U.S. Gov't

Fingerprint Dive into the research topics of 'Intracerebroventricular injection of a nitric oxide synthase inhibitor does not affect long-term slope potentiation in vivo'. Together they form a unique fingerprint.

Cite this