Distribution of ORL-1 receptor binding and receptor-activated G-proteins in rat forebrain and their experimental localization in anterior cingulate cortex

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• 作者：Sim-Selley ; Laura J. ; Vogt ; Leslie J. ; Childers ; Steven R. ; Vogt ; Brent A.
• 关键词：Nociceptin ; Orphanin FQ ; Opioid receptor ; Nociception ; ACC ; Anterior cingulate cortex ; ACo ; Cortical nucleus of the amygdala ; AHi ; Amygdalohippocampal area ; AI ; Agranular insular cortex ; AO ; Anterior olfactory nucleus ; Arc ; Arcuate nucleus ; AV ; Anterovent
• 刊名：Neuropharmacology
• 出版年：2003
• 出版时间：August, 2003
• 年：2003
• 卷：45
• 期：2
• 页码：220-230
• 全文大小：1.40 M

文摘

Opioid receptor-like (ORL-1) receptors and ORL-1-activated G-proteins are found in high levels in the forebrain, particularly cingulate cortex, an area involved in processing of nociceptive stimuli. [³H]nociceptin/orphanin FQ (N/OFQ) and N/OFQ-stimulated [³⁵S]GTPγS autoradiography in rat brain were used to localize ORL-1 receptors and activated G-proteins, respectively. N/OFQ binding and activated G-proteins were highest in anterior cingulate, agranular insula, piriform, perirhinal and entorhinal cortices; midline and intralaminar thalamic nuclei; and subnuclei of the amygdala and hippocampus. In anterior cingulate area 24, [³H]N/OFQ and N/OFQ-stimulated [³⁵S]GTPγS binding were highest in layers V and VI. The cellular localization of ORL-1 receptors and activated G-proteins in area 24 was examined using two strategies: ibotenic acid injection into the cortex or undercut lesions to remove afferent axons, followed by autoradiography. Ibotenic acid lesions that destroyed neurons in the anterior cingulate cortex decreased [³H]N/OFQ binding by 75–80 % and reduced N/OFQ-stimulated [³⁵S]GTPγS binding to basal levels seen in the absence of agonist. Deafferentation lesions increased [³H]N/OFQ binding by 40–50 % , with no significant change in N/OFQ-stimulated [³⁵S]GTPγS binding. These data demonstrate that ORL-1 receptors in layer V of anterior cingulate cortex are located on somatodendritic elements and that deafferentation increases ORL-1 receptor binding.