Striatal opioid receptor availability is related to acute and chronic pain perception in arthritis: does opioid adaptation increase resilience to chronic pain?

ABSTRACT: The experience of pain in humans is modulated by endogenous opioids, but it is largely unknown how the opioid system adapts to chronic pain states. Animal models of chronic pain point to upregulation of opioid receptors (OpR) in the brain, with unknown functional significance. We sought evidence for a similar relationship between chronic pain and OpR availability in humans. Using positron emission tomography and the radiotracer (11)C-diprenorphine, patients with arthritis pain (n = 17) and healthy controls (n = 9) underwent whole-brain positron emission tomography scanning to calculate parametric maps of OpR availability. Consistent with the upregulation hypothesis, within the arthritis group, greater OpR availability was found in the striatum (including the caudate) of patients reporting

SUBMITTER: Brown CA 

PROVIDER: S-EPMC4933204 | biostudies-literature | 2015 Nov

REPOSITORIES: biostudies-literature