Neurobiology of learning and memory
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Neurobiol Learn Mem · May 2008
Ethanol state-dependent memory: involvement of dorsal hippocampal muscarinic and nicotinic receptors.
In the present study, the effects of bilateral injections of cholinergic agents into the hippocampal CA1 regions (intra-CA1) on ethanol state-dependent memory were examined in mice. A single-trial step-down passive avoidance task was used for the assessment of memory retention in adult male NMRI mice. Pre-training intraperitoneal injection (i.p.) of ethanol (0.25, 0.5 and 1g/kg) dose dependently induced impairment of memory retention. ⋯ Pre-test intra-CA1 injection of the muscarinic receptor antagonist, atropine (4 and 8 microg/mouse, intra-CA1) or the nicotinic receptor antagonist, mecamylamine (2 and 4 microg/mouse, intra-CA1) 5 min before the administration of ethanol (1g/kg, i.p.) dose dependently inhibited ethanol state-dependent memory. Pre-test intra-CA1 administration of physostigmine (0.5, 2.5 and 5 microg/mouse), atropine (2, 4 and 8 microg/mouse), nicotine (0.1, 0.3 and 0.5 microg/mouse) or mecamylamine (1, 2 and 4 microg/mouse) alone cannot affect memory retention. These findings implicate the involvement of a dorsal hippocampal cholinergic mechanism in ethanol state-dependent memory and also it can be concluded that there may be a cross-state dependency between ethanol and acetylcholine.