Hippocampal muscarinic acetyolcholine receptors modulate memory reconsolidation of an inhibitory avoidance task in mice

KRAWCZYK MC; BOCCIA MM; BLAKE MG; BARATTI CM

Huerta Grande, Córdoba

Congreso; XXVII Congreso Anual de la Sociedad Argentina de Investigación en Neurociencias; 2012

Sociedad Argentina de Investigación en Neurociencias

CF-1 male mice were trained in an inhibitory avoidance task using either a mild or a high footshock. A retention test was given 48 hours later. Immediately after it, mice were given intra-dorsal hippocampus infusions of either oxotremorine (OXO, a muscarinic acetylcholine receptor agonist, 1.00-10.00 ng/hippocampus), or scopolamine (SCO, a muscarinic acetylcholine receptor antagonist, 1.00-10.00 ug/hippocampus). Memory retention was tested again 24 h later. SCO impaired retention performance regardless of footshock intensit. OXO impaired retention performance only in those mice trained with a high footshock. On the contrary, OXO enhanced retention performance when mice were trained with a mild footshock. These effects were dose- and timedependent. Retention performance was not affected in drug-treated mice that were not subjected to memory reactivation, suggesting that the performance effects cloud not be attributable to non-specific effects of the drugs. Our results suggest for the first time that hippocampal muscarinic acetylcholine receptors play a critical role in reconsolidation of an inhibitory avoidance response in mice.