Morphine Addiction and Its Withdrawal Effects on Prefrontal Cortex Using Concurrent Study of LFP and OISi

Opiates are among the widely abused substances worldwide. Also, the clinical use of opioids can cause unwanted and potentially serious consequences such as developing tolerance and dependence. In this study, we simultaneously measured the changes induced after morphine dependence and naloxone-induced withdrawal syndrome on the resting state functional connectivity (rsFC) and local field potential (LFP) power in prefrontal cortex of the rat. Our results revealed that acute morphine administration significantly increased the LFP power in all frequency bands as well as the rsFC strength of the prefrontal cortex, and naloxone injection reversed this effect. In contrast, chronic morphine administration reduced neural activity and general correlation values in intrinsic signals as well as the LFP power in all frequency bands. In addicted rats, after each morphine administration, the LFP power in all frequency bands as well as the rsFC strength of the prefrontal cortex were increased and these effects were further enhanced after naloxone precipitated withdrawal syndrome. We conclude that general correlation merely reflects the field activity of the local cortices imaged.