EVALUATION OF THE GENE EXPRESSION LEVEL OF OREXIN-1 RECEPTOR IN THE RAT NUCLEUS ACCUMBENS AND PREFRONTAL CORTEX AND ITS RELATIONSHIP WITH PRONENESS TO METHAMPHETAMINE DEPENDENCE

Background and Aim : Drug addiction is a major social and economic problem in human societies. Orexin-1 receptors (OX1Rs) promote reward intake under conditions of strong drives for reward, including drug taking. Systemic modulation of OX1Rs can alter drug taking. The brain regions that mediate this OX1R during drug taking remain unknown. Given the importance of the nucleus accumbens (NAc) and prefrontal cortex (PFC) in driving many addictive behaviors, including OX1Rs within these regions, we have investigated the correlation between the gene expression level of orexin-1 receptor (OX1R) in the rat prefrontal cortex (PFC) and nucleus accumbens (NAc) and susceptibility to METH dependence.Methods : 32 male Wistar rats were first examined for the susceptibility to METH abuse by voluntary METH oral consumption test. According to the amounts of METH consumption, the animals were divided into two groups of METH prefer and non-prefer. Then the rats in each group were sacrificed and the level of OX1R in their NA and PFC tissue was measured by real-time PCR. Results : the expression level of OX1R in the NA and PFC in the prefer group was considerably higher than the non-prefer group. This difference was statistically significant (P <0.05).Conclusion : Up-regulation of the mRNA expression level of OX1R in the nucleus accumbens and prefrontal cortex may serve as a potential biomarker and facilitator for methamphetamine dependence, and the purpose of the treatment for METH addiction.

کلیدواژه ها:

gene expression ، orexin receptors ، methamphetamine dependence ، NA ، PFC