Brain Reward Circuits in Morphine Addiction

Abstract

Morphine is the most potent analgesic for chronic pain, but its clinical use has been limited by the opiate’s innate tendency to produce tolerance, severe withdrawal symptoms and rewarding properties with a high risk of relapse. To understand the addictive properties of morphine, past studies have focused on relevant molecular and cellular changes in the brain, highlighting the functional roles of reward-related brain regions. Given the accumulated findings, a recent, emerging trend in morphine research is that of examining the dynamics of neuronal interactions in brain reward circuits under the influence of morphine action. In this review, we highlight recent findings on the roles of several reward circuits involved in morphine addiction based on pharmacological, molecular and physiological evidences.

Treatment of opioid dependence with buprenorphine/naloxone sublingual tablets: A phase 3 randomized, double‐blind, placebo‐controlled trial

“…Craving and withdrawal symptoms, which increase the likelihood of relapse (Heinz et al, ; Kim, Ham, Hong, Moon, & Im, ), were also considered as a basis for efficacy of treatment. Results from this study indicate that opioid withdrawal symptoms were significantly milder in patients receiving buprenorphine/naloxone compared with those receiving placebo.…”

Basic/Translational Development of Forthcoming Opioid- and Nonopioid-Targeted Pain Therapeutics

“…149 Higher order action on forebrain structures have additionally been identified 145 and likely reflect upon the effects of opioids on distress. 150 Recent work has suggested possible efficacy of kappa opioid antagonists as a migraine therapeutic. 302 Preclinical actions of opioids and their effects mediated through the several opioid receptors on pain behavior after systemic and spinal delivery have been reviewed extensively.…”

Quantifying absolute glutamate concentrations in nucleus accumbens of prescription opioid addicts by using 1H MRS

“…Most previous studies of drug addiction's effect on brain systems have focused on illicit drugs, such as heroin, cocaine, cannabis (Greenwald, Woodcock, Khatib, & Stanley, 2015;Paydary et al, 2016;Rodriguez-Cintas et al, 2016), as opposed to legal opiates (e.g., codeine, morphine, and opium) (Kim, Ham, Hong, Moon, & Im, 2016;Qiu, Su, Lv, & Jiang, 2015;Schuckit, 2016). Long-term use of prescription opioid exposes patients to risk of developing addictive side effects, such as rewarding and withdrawal symptoms (Kim et al, 2016).…”

“…Proton magnetic resonance spectroscopy ( 1 H MRS) is a noninvasive evaluation that provides in vivo quantification of the concentrations of selected biochemicals. The brain's reward circuitry is the neuroanatomical basis of producing the reward effect in psychoactive substance dependence (Kim et al, 2016;Koob & Volkow, 2010;Russo & Nestler, 2013). The nucleus accumbens (NAc) is one of the most important nuclei in the reward circuitry, and acts as an interface for the transfer of information between the limbic and motor systems (Mavridis, Boviatsis, & Anagnostopoulou, 2011;Zhu et al, 2016).…”