Chronic restraint stress facilitates the acquisition of cocaine self-administration.

AVALOS MARIA PAULA; BOLLATI FLAVIA; GUZMAN ANDREA SUZANA; GARCIA-KELLER CONSTANZA; CANCELA LILIANA M

Congreso; XXX Congreso Anual de la Sociedad Argentina de Investigación en Neurociencias; 2015

Sociedad Argentina de Investigación en Neurociencias

Clinical evidence supports theidea of individuals that suffer stressing events along their lives arevulnerable to developing substance use disorders (SUDs). Here, we attempted tomimic how exposure to chronic stressful life events can create a vulnerabilityto developing SUDs. Sprague-Dawley rats were exposed to chronic restraintstress (2 hs daily) during seven days. A week after the last stress session,all animals were anesthetized and implanted with indwelling jugular catheters.Seven days after surgery, rats began daily 2 hs cocaine self-administration(SA) sessions (fixed ratio 1), in which one response on the active leveryielded one intravenous cocaine infusion (0.2 mg/infusion, followed by a 5 stime-out period), paired with a white cue light above the active lever and adiscrete tone cue. An inactive lever was also available throughout each session.Rats were allowed ten days to reach SA criterion, which was defined as thefirst day animals obtaining more than ten infusions of cocaine. Our results pointout a facilitation of the acquisition of cocaine SA as well an augmented intakeof cocaine in pre-stressed animals as regard to control unstressed animals.This behavioral facilitation induced by chronic stress on cocaine SA was provedby quantifying the ratio of response on the active lever and the amount ofcocaine infusions, these findings constitute a starting platform to study themechanisms underpinning the comorbility between stress and SUDs.