ROLE OF CB1 RECEPTOR IN VULNERABILITY TO MORPHINE DEPENDENCE IN ADOLESCENT MICE PRENATALLY EXPOSED TO A CANNABINOID AGONIST

SORIANO, DELIA; BRUSCO, ALICIA; VARANI, ANDRES; BALERIO, GRACIELA; CALTANA, LAURA ROMINA; PEDRON, VALERIA

Congreso; 6TH INTERNATIONAL DRUG ABUSE RESEARCH SOCIETY MEETING; 2017

Cannabinoids and opioids are psychoactive drugs with similar pharmacological effects, asboth produce analgesia, catalepsy, hypothermia, motor depression, hypotension and rewardeffects. CB1 receptor is involved in the motivational properties of opiates and in thedevelopment of dependence. The close relationship between cannabinoid and opioid systemsis critical during morphine (MOR) withdrawal. CD1 mice deficient in cannabinoid receptortype 1 (CB1 knockout) have a lower intensity of somatic signals to MOR withdrawal inducedby naloxone (NAL) as compared to wild-type CD1 mice (WT).The current work studied: 1) gender differences in the somatic syndrome during MORwithdrawal induced by NAL in CB1 knockout and WT; 2) the effect of prenatal exposure toWIN 55.212-2 (WIN) on the expression of MOR withdrawal in adolescent CB1 knockoutand WT. Primiparous pregnant CB1 knockout and WT received WIN or vehicle fromgestational day 5; after delivery, dams were replaced by naive substitutes. The MORdependence and withdrawal protocol was implemented in pups at postnatal day 25.Results: 1) No gender-specific differences were detected between pups; 2) Prenatal exposureto WIN reduced MOR withdrawal expression in WT but not in CB1 knockout, whose MORwithdrawal expression levels showed no significant differences from their vehiclecounterparts (p