Region-specific up-regulation of opioid receptor binding in enkephalin knockout mice.
Mu and delta opioid receptors were labeled in enkephalin knockout mice by quantitative autoradiography. Discrete, large increases (100-300%) were found in limbic forebrain structures for mu binding and striatum and pallidum for delta binding. The up-regulation of opioid receptors may reflect a form of 'denervation supersensitivity. ' The receptor up-regulation in limbic areas is consistent with the increased emotional and aggressive behaviors observed in the enkephalin knockout mice.
D000818:Animals; D001345:Autoradiography; D001921:Brain / Q000378:metabolism*; D004745:Enkephalins / Q000235:genetics*; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D017465:Receptors, Opioid, delta / Q000378:metabolism*; D017450:Receptors, Opioid, mu / Q000378:metabolism*; D015854:Up-Regulation