Acute morphine exposure increases the brain distribution of [18F]DPA-714, a PET biomarker of glial activation in nonhuman primates

Abstract

Background: The neuroinflammatory response to morphine exposure modulates its antinociceptive effects, tolerance, and dependence. Positron emission tomography radioligands for translocator protein-18kDa such as [18F]DPA-714 are noninvasive biomarkers of glial activation, a hallmark of neuroinflammation. Methods: [18F]DPA-714 positron emission tomography imaging was performed in 5 baboons at baseline and 2 hours after i.m. morphine injection (1 mg/kg). Brain kinetics and metabolite-corrected input function were measured to estimate [18F]DPA-714 brain distribution. Results: Morphine significantly increased [18F]DPA-714 brain distribution by a 1.3 factor (P