Dr. Susruta Majumdar: NIDA-supported basic science is also shedding important light on opioids and the brain’s opioid signaling systems. Research published in June in ACS Central Science provided new insights while raising new questions about the drug kratom. Its active ingredient mitragynine acts as a weak partial agonist at the mu-opioid receptor (MOR), but new findings by a team that included researchers at Columbia and Memorial Sloan-Kettering found that the drug’s analgesic properties are significantly mediated by a metabolite produced when mitragynine is consumed orally, called 7-hydroxymitragynine. In mice, at least, this compound seems to provide analgesia but with fewer respiratory-depressing and reward-associated side effects than other opioids such as morphine. These findings point toward the potential of this drug in pain research as well as the need for further research on the pharmacology of kratom’s constituents, their toxicity and potential value in the treatment of OUD.
Drs. Ream Al-Hasani & Jordan McCall: Although the MOR system is most commonly associated with pain and pain relief, other receptors are also involved. One important dimension of pain is the negative affect commonly associated with it, and NIDA-supported research published in Neuron in March found that the kappa-opioid signaling system, specifically in cells located in the shell of the nucleus accumbens, are involved in processing pain-associated negative affect. This discovery could perhaps provide new targets for treating the emotional distress associated with many pain-associated syndromes.
Read NIDA’s full article here: https://www.drugabuse.gov/about-nida/noras-blog/2020/01/reviewing-nidas-2019-achievements-looking-to-future