Disruption of fear memory reconsolidation by an appetitive stimulus in ethanol withdrawn rats pre-treated with D-cycloserine

Congreso; XXIX Congreso anual de la Sociedad Argentina de Investigación en Neurociencia; 2014

SOCIEDAD ARGENTINA DE NEUROCIENCIAS

We have recently reported that a contextual fear memory formed during ethanol (ETOH) withdrawal is resistant to pharmacological disruption after recall. D-cycloserine (DCS, a NMDA receptor partial agonist) administration before memory reactivation promoted vulnerability to the disruptive effect of propranolol on fear memory reconsolidation in ETOH withdrawn rats. Here, we examined whether the memory reconsolidation process can be impaired by the presentation of an appetitive stimulus after retrieval in ETOH withdrawn rats. Male Wistar rats made dependent via an ETOH containing liquid diet (6% v/v) for 14 days. Contextual fear conditioning was performed 3 days after withdrawal. The following two days, animals received alcohol-free beer (BEER) for 2 hours/day. The next day, rats received DCS (5 mg/kg i.p) or saline (SAL) 30 min before a 5 min retrieval session. Fifteen minutes after, animals were given 2 hours access to BEER. Memory retention was evaluated one and seven days later. An affective attenuation of freezing was observed in DCS/BEER treated ETOH group, SAL/BEER and DCS/BEER treated control animals. However, SAL/BEER treatment was ineffective in ETOH group. These effects lasted up to one week. These findings strengthen our assumption that ethanol withdrawal facilitates the formation of fear memory resistant to labilization after recall. On the other hand, they indicate that DCS/BEER is an effective disruptor of fear memory reconsolidation in ETOH dependent rats.