Opposing Effects on Descending Control of Nociception by µ and κ Opioid Receptors in the Anterior Cingulate Cortex

ConclusionsAnterior cingulate cortex κ opioid receptor activation therefore diminishes descending control of nociception both in naive animals and as an adaptive response to chronic pain, likely by enhancing net descending facilitation. Descending control of nociception can be restored by activation of μ opioid receptors in the anter ior cingulate cortex, but also by κ opioid receptor antagonists, providing a nonaddictive alternative to opioid analgesics. Navacaprant is now in advanced clinical trials.Editor ’s PerspectiveWhat We Already Know about This TopicThe prevalence and severity of chronic pain are influenced by endogenous pain control mechanismsOpioids regulate the efficiency of endogenous pain control circuits including those arising in the anterior cingulate cortexWhat This Article Tells Us That Is NewMicroinjection of κ opioid receptor antagonists into the anterior cingulate cortex of nerve injured rats restored descending control of nociception, an endogenous pain control circuitMicroinjection of selective κ opioid receptor agonists reduced descending control of nociception in sham injured rats confirming the importance of the κ opioid receptor in regulating endogenous pain control
Source: Anesthesiology - Category: Anesthesiology Source Type: research