Kalyuzhny A E, Dooyema J, Wessendorf M W
Department of Neuroscience, University of Minnesota, Minneapolis 55455, USA.
Neuroreport. 2000 Aug 21;11(12):2625-8. doi: 10.1097/00001756-200008210-00004.
Pharmacological data suggest that opioids exert their excitatory action in brain indirectly, by inhibiting release of the inhibitory neurotransmitter GABA. However, it is also possible that single neuron may interact with both opioids and GABA. In the present study, we investigated whether neurons in rat midbrain and medulla express both opioid and GABA(A) receptors. Coronal sections through rat brain were double-stained using antibodies against the alpha 1 subunit of GABA(A) receptor that were combined with antibodies either against the cloned mu-opioid receptor (MOR1) or the cloned kappa-opioid receptor (KOR1). Neurons double-labeled for GABA(A) receptors and either MOR1 or KOR1 were found in many brain regions including inferior colliculus, mesencephalic trigeminal nuclei, pontine reticular nuclei and raphe interpositus nucleus. Neurons double-labeled for GABA(A) and MOR1 were observed less frequently than those labeled for GABA(A) and KOR1. Our findings provide anatomical evidence that GABAergic and opioidergic systems are closely linked and activity of the same neuron may be regulated directly by both GABA and opioids.
药理学数据表明，阿片类药物通过抑制抑制性神经递质γ-氨基丁酸（GABA）的释放，间接在大脑中发挥其兴奋作用。然而，单个神经元也可能同时与阿片类药物和GABA相互作用。在本研究中，我们调查了大鼠中脑和延髓中的神经元是否同时表达阿片受体和GABA（A）受体。使用针对GABA（A）受体α1亚基的抗体与针对克隆的μ-阿片受体（MOR1）或克隆的κ-阿片受体（KOR1）的抗体相结合，对大鼠脑的冠状切片进行双重染色。在许多脑区发现了同时标记有GABA（A）受体和MOR1或KOR1的神经元，包括下丘、中脑三叉神经核、脑桥网状核和中间缝际核。同时标记有GABA（A）和MOR1的神经元比标记有GABA（A）和KOR1的神经元出现的频率更低。我们的研究结果提供了解剖学证据，表明GABA能系统和阿片肽能系统紧密相连，同一神经元的活动可能直接受到GABA和阿片类药物的调节。
