Background and Aim : It is likely that BDNF is necessary to plasticity induced by opiates in the dopaminergic neurons for the morphine-induced conditioned place preference. Therefore، this study examined the effects of BDNF receptor antagonist (ANA-12) on the mpFC and Extinction and reinstatement of morphine-induced conditioned place preference (CPP)
mPFC BDNF levels and apoptotic cells in rats.Methods : In this study،48 adult male Wistar rat (200-250 g) wera used. The rewarding properties of morphine were investigated using a CPP paradigm consisted of 5-day schedule with three distinct phases: pre-conditioning, conditioning and post- conditioning. Bilateral guide cannulas were stereotaxically implanted into the central region of the
mPFC in rats. Rats were then trained in the CPP after the recovery period. To assess،ANA-12To assess the effect of ANA-12 on extinction،after a conditioning test day an ANA-12 is injected for three days and after 5 daysextintion،test Post Conditioninand toreinstatement assess 5day, and the day before the test reinstatement of the rat a test extinction was performed to ensure the extinction period. On the day ofreinstatement ANA-12, it was injected in the frontal cortex area and 15 minutes later a neutral dose of morphine was injected intraperitoneally.Then, the levels of BDNF and apoptotic cellsof the
mPFC were assessed at the end of each treatment phase using ELISA and TUNEL methods respectively.Results : The results of this study indicated that intra-mPFC injections of ANA-12 significantly attenuated the extinction of morphine-induced CPP.but there was no significant effect of BDNF onthe median prefrontal cortex.But in the ANA-12 Reinstatement group, there is no significant in the preferences of the conditional place.Also, the level of BDNF in the receiving group of ANA-12did not significant difference with receiving vehicle group.As well as antagonizing the BDNF on motor activity rat is ineffective.Conclusion : This study demonstrated that central administration of ANA-12 in the
mPFC attenuates the o fextinction and reinstatement morphine-induced CPP, via a TrkB-mediated mechanism