Region-specific up-regulation of opioid receptor binding in enkephalin knockout mice

• Published in: Brain research. Molecular brain research. Vol. 68; no. 1; pp. 193 - 197
• Main Authors: Brady, Linda S, Herkenham, Miles, Rothman, Richard B, Partilla, John S, König, Monica, Zimmer, Anne M, Zimmer, Andreas
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 07-05-1999; Elsevier
• Subjects: Amygdala; Animals; Autoradiography; Biological and medical sciences; Brain - metabolism; Central nervous system; Central neurotransmission. Neuromudulation. Pathways and receptors; Enkephalin; enkephalins; Enkephalins - genetics; Fundamental and applied biological sciences. Psychology; Hypothalamus; Knockout; Male; Mice; Mice, Knockout; Opioid receptor; Receptors, Opioid, delta - metabolism; Receptors, Opioid, mu - metabolism; Up-Regulation; Vertebrates: nervous system and sense organs; Autoradiography; Hypothalamus; Amygdala; Opioid receptor; Knockout; Enkephalin; Targeting; Rodentia; Central nervous system; Neuropeptide; Opioid peptide; Vertebrata; Mammalia; Gene; Mouse; Mutation; Brain (vertebrata)
• ISSN: 0169-328X; 1872-6941
• DOI: 10.1016/S0169-328X(99)00090-X

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.