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

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 GABAA 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 GABAA 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 GABAA receptors of the dorsal hippocampal may play an important role in ACPA-induced amnesia and ACPA state-dependent memory.