Perinatal protein malnutrition facilitates morphine's cross-sensitization to cocaine in adult rats: a behavioral study

PERONDI M.C.; TORTONI G.; VALDOMERO A.; CUADRA G.

Huerta Grande, Córdoba

Congreso; XXVIII Reunión Anual de la Sociedad Argentina de Investigaciones en Neurociencias; 2013

Sociedad Argentina de Investigaciones en Neurociencias (SAN)

In order to evaluate the influence of early malnutrition on the development of behavioral cross-sensitization to rewarding properties of cocaine in adult rats, different groups of control (C) and deprived (D) rats were pretreated twice a day for three days with increasing doses of morphine (5, 10 and 20 mg/ kg, s.c.). After the sensitization phase, the rewarding effect of cocaine was assessed in D-rats and C-rats using the Conditioned Place Preference (CPP) paradigm. Dose-response curves to cocaine (3, 5, 7.5 and 10 mg/kg i.p.) revealed in D-rats a conditioning effect with doses of 5, 7.5 and 10 mg/kg, whereas 3 mg/kg did not show conditioning effect. In C-rats, cocaine elicited place preference only with the higher dose of 10 mg/kg. Thus, when the animals where pretreated twice a day for three days with escalating doses of morphine only D-rats showed sensitization to the conditioning effect with the low doses of cocaine (5 and 7.5 mg/kg i.p.). These results suggest that a deficient nutritional status during early life may induce in adult subjects a lower threshold for developing a behavioral cross-sensitization to cocaine. The possibility that changes in reactivity may be due to pharmacokinetic alterations induced by early undernutrition may be ruled out, since similar brain and plasma morphine / cocaine levels were found in both groups of rats.