Changes in the electrical activity of prefrontal neurons following methamphetamine-induced conditioned place preference in the rat

Introduction: Methamphetamine (METH) addiction is an epidemic-growing problem globally. Studies confirmed a solid linkage between the prefrontal cortex (PFC) and drug -seeking. The present study aimed to investigate PFC neural activity changes after injection of METH following METH-induced conditioned place preference (CPP) in the rats.Methods: After the development of CPP (0.5mg/kg METH for three days, SC), in vivo single-unit recordings were carried out the day after the post-test (post-conditioning day). On recording day, after stabilization and baseline recording (a 10-min period), the injection of METH (0.5mg/kg, SC) was performed and then, PFC neural activity was recorded for a 30-min period.Results: The results revealed that the injection of METH on the post-conditioning test significantly increases PFC neurons' firing rate in animals that received METH during the CPP paradigm.Conclusion: It seems that maybe, PFC neurons appear to be implicated in the associated METH reward pathway and repeated exposure to METH affected the sensitivity of neurons in this area.