Hippocampal ERK1/ERK2 activation after memory reconsolidation modulation by

KRAWCZYK MC; FELD M; BLAKE MG; BARATTI CM; BOCCIA MM

Huerta Grande, Córdoba

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

Sociedad Argentina de Investigación en Neurociencias

Previously we reported that hippocampal alpha-7 nicotinic acetylcholine receptors (nAChRs) play a critical role in reconsolidation of an inhibitory avoidance response. Extracellular signal-regulated kinases (ERK) were demonstrated to be involved in downstream signaling after 7nAchRs activation. CF-1 male mice were trained in an inhibitory avoidance task using either a mild or a strong footshock. A retention/reactivation test was given 48 hours later. Immediately after it, mice were given intra-dorsal hippocampal infusions of choline, a alpha-7nAchRs agonist (Ch, 0.80 ug/hippocampus) or methyllycaconitine, a alpha-7nAchRs antagonist (MLA, 10.00 ug/hippocampus). Fifteen minutes after the infusion, the hippocampi were dissected and ERK1/ERK2 activation was determined either in the nuclear and the cytosolic fractions. ERK1/ERK2 was activated differentially, depending on the training conditions (mild or strong footshock), after memory reactivation. Ch or MLA, given immediately after memory reactivation, modified ERK1/ERK2 pattern of activation. Altogether, our results suggest for the first time a molecular pathway pattern of activation (activation or inactivation) that correlates with memory reconsolidation modulation (enhancement or impairment).