Chronic cocaine alters brain mu opioid receptors

EM Unterwald, J Horne-King, MJ Kreek - Brain research, 1992 - Elsevier
EM Unterwald, J Horne-King, MJ Kreek
Brain research, 1992Elsevier
The possibility that dopamine may modulate the expression of opioid receptors was
investigated by determining the effects of chronic cocaine administration on the density of μ
opioid receptors. Quantitative in vitro autoradiography with the highly selective μ opioid
ligand [3 H] DAMGO was used to measure and localize changes in μ opioid receptors in the
brains of rats administered cocaine or saline three times daily for 14 days. Significant
increases in [3 H] DAMGO binding were measured in areas of the cingulate cortex, nucleus …
Abstract
The possibility that dopamine may modulate the expression of opioid receptors was investigated by determining the effects of chronic cocaine administration on the density of μ opioid receptors. Quantitative in vitro autoradiography with the highly selective μ opioid ligand [3H]DAMGO was used to measure and localize changes in μ opioid receptors in the brains of rats administered cocaine or saline three times daily for 14 days. Significant increases in [3H]DAMGO binding were measured in areas of the cingulate cortex, nucleus accumbens, caudate putamen, and basolateral amygdaloid nucleus of the cocaine-treated animals. These results demonstrate that μ opioid receptors undergo upregulation in response to chronic cocaine exposure and suggest that dopamine activity can regulate the expression of μ opioid receptors.
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