Oscillatory activity and LFP power modulation in the hippocampal CA1 and prelimbic cortex during morphine-induced place preference.

Morphine use disorder (MUD) is a complex neurobiological condition characterized by the reinforcement of addictive behaviors and the development of both psychological and physical dependence. The euphoric effects induced by morphine are mediated by key brain regions, including the CA1 region of the hippocampus and the prelimbic cortex (PrL). This study investigates the neural dynamics underlying morphine's effects on reward processing by examining local field potentials (LFP) in the CA1 and PrL regions during morphine-induced conditioned place preference (CPP). LFP recordings from male Wistar rats reveal significant changes in oscillatory activity in response to morphine administration during both the conditioning and reinstatement phases of the CPP paradigm. Specifically, morphine enhanced theta and high-gamma power in the CA1 region, reflecting increased hippocampal activity associated with drug-reward memory. Additionally, coherence between the CA1 and PrL regions in the theta frequency band was significantly altered, suggesting enhanced communication between these areas during drug craving behavior. These findings underscore the role of neural oscillations, particularly in the theta band, in morphine-induced reward memory formation and the reinstatement of drug-seeking behavior. This research provides insights into the neurophysiological mechanisms of MUD and highlights potential targets for developing therapeutic strategies aimed at addiction treatment.