Volume 7 Supplement 1

International Society on Brain and Behaviour: 3rd International Congress on Brain and Behaviour

Open Access

Involvement of GABA-B receptors of the dorsal hippocampus in the inhibition of morphine-induced amnesia by morphine sensitization

  • Mohammad-Reza Zarrindast1, 2,
  • Vahid Hoghooghi1 and
  • Ameneh Rezayof3
Annals of General Psychiatry20087(Suppl 1):S207

https://doi.org/10.1186/1744-859X-7-S1-S207

Published: 17 April 2008

Background

Our previous studies show that pre-training administration of morphine induces amnesia [1] and this effect was significantly reduced in morphine-sensitized mice [2]. In the present study the role of GABA-B receptors of the dorsal hippocampus in the inhibition of morphine-induced amnesia by morphine sensitization were investigated in mice.

Materials and methods

A single-trial step-down passive avoidance task was used for the assessment of memory retention in adult male NMRI mice. Animals were bilaterally cannulated in the CA1 regions by stereotaxic instrument, and were allowed to recover 1-week before behavioral testing.

Results

Morphine-induced amnesia was reversed in morphine-sensitized mice which had previously received once daily injections of morphine for 3 days. The inhibition of morphine-induced amnesia in animals that had previously received the 3-days morphine treatment was significantly decreased by once daily injections of the different doses of GABA-B receptor agonist, baclofen prior to s.c. injections of morphine. Amnesia induced by pre-training morphine had no significant change in mice which had previously received once daily injections of CGP35348 plus an ineffective dose of morphine for 3 days.

Conclusions

The present results indicate that GABA-B receptors of the dorsal hippocampus may play an important role in the inhibition of morphine-induced amnesia by morphine sensitization.

Authors’ Affiliations

(1)
Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences
(2)
School of Cognitive Science, Institute for Studies in Theoretical Physics and Mathematics
(3)
Department of Animal Biology, School of Biology, College of Science, University of Tehran

References

  1. Zarrindast MR, Jafari-Sabet M, Rezayat M, Djahanguiri B, Rezayof A: Involvement of NMDA receptors in morphine state-dependent learning. Intern J Neuroscience. 2006, 116: 1-13. 10.1080/00207450690962208.View ArticleGoogle Scholar
  2. Zarrindast MR, Rezayof A: Morphine state-dependent learning: sensitization and interactions with dopamine receptors. Eur J Pharmacol. 2004, 497: 197-204. 10.1016/j.ejphar.2004.06.041.View ArticlePubMedGoogle Scholar

Copyright

© Zarrindast et al.; licensee BioMed Central Ltd. 2008

This article is published under license to BioMed Central Ltd.

Advertisement