[Influence of dorsal hippocampal GABA receptors on state-dependent learning induced by CB1 cannabinoid receptors agonist in mice]

ABSTRACT

Cannabinoids exert widespread effects on cognitive functions. An overlapped distribution of GABA receptors and cannabinoid receptors has been reported in some brain structures [e.g. dorsal hippocampus]. Thus, the present study was undertaken to examine the possible role of the dorsal hippocampus GABA[A] receptors on ACPA induced amnesia and ACPA state-dependent memory. This experimental study was conducted on 250 adult male NMRI mice. Muscimol and ACPA were used as agonists of GABA[A] and the cannabinoid CB1 receptors, respectively. Mice were anaesthetized and cannulae were implanted bilaterally into the CA1 regions of the dorsal hippocampus. Seven days after post-surgery recovery, the behavioral testing was performed using an inhibitory avoidance task and the step-down latency of the animals was used to assess memory retention. Post-training administration of ACPA [3ng/mouse] impaired the memory retrieval. The memory impairment induced by ACPA was fully reversed by pre-test administration of ACPA or muscimol. The results suggest that the GABA[A] receptors of the dorsal hippocampal may play an important role in ACPA-induced amnesia and ACPA state-dependent memory