Opiate receptor gradients in monkey cerebral cortex: correspondence with sensory processing hierarchies.
In order to obtain information on the possible functions of endogenous opiates in the primate cerebral cortex, we assessed the distribution of mu-like opiate receptors (which selectively bind 3H-labeled naloxone) and delta-like opiate receptors (which selectively bind 3H-labeled D-Ala2, D-Leu5-enkephalin) throughout the cerebral cortex of the rhesus monkey. Stereospecific [3H]naloxone binding sites increased in a gradient along hierarchically organized cortical systems that sequentially process modality-specific sensory information of a progressively more complex nature. Specific [3H]enkephalin binding sites, in contrast, were relatively evenly distributed throughout the cerebral cortex. These results, in combination with electrophysiological studies of monkeys and humans, suggest that mu-like opiate receptors may play a role in the affective filtering of sensory stimuli at the cortical level, that is, in emotion-induced selective attention.
D000818:Animals; D001303:Auditory Cortex / Q000378:metabolism; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000378:metabolism*; D004745:Enkephalins / Q000378:metabolism; D005260:Female; D008253:Macaca mulatta; D008297:Male; D009270:Naloxone / Q000378:metabolism; D011957:Receptors, Opioid / Q000378:metabolism*; D014793:Visual Cortex / Q000378:metabolism
D004745:Enkephalins; D011957:Receptors, Opioid; D009270:Naloxone