Takayama H, Mizukawa K, Ota Z, Ogawa N
Third Department of Internal Medicine, Okayama University Medical School, Japan.
Brain Res. 1987 Dec 15;436(2):291-5. doi: 10.1016/0006-8993(87)91673-8.
The effect of immobilization stress (IM-stress) on the muscarinic cholinergic (m-Ch) receptor binding was determined in 8 brain regions using [3H]quinuclidinyl benzilate (QNB). IM-stress produced an increase in specific QNB binding in the septum, striatum, hippocampus and pons + medulla oblongata. Scatchard analysis revealed that IM-stress produced an increase in the affinity of m-Ch receptors in the septum, hippocampus and pons + medulla oblongata, but did not alter the maximum number of binding sites (Bmax). In the striatum, an increase in specific QNB binding was due to both the increase in Bmax and reduction of the dissociation constant (Kd). The present study suggests that IM-stress induces supersensitivity of postsynaptic m-Ch receptors probably due to a decrease in presynaptic cholinergic activities in the septum, striatum, hippocampus and pons + medulla oblongata. As the m-Ch receptors in the striatum and pons + medulla oblongata are affected by IM-stress, further studies of the m-Ch neural system must be performed under stressful situations in these regions as well as in the septum, hippocampus and cerebral cortex.
使用[3H]喹核醇基苯甲酸酯（QNB）测定了固定应激（IM应激）对8个脑区毒蕈碱胆碱能（m-Ch）受体结合的影响。IM应激使隔区、纹状体、海马以及脑桥+延髓的特异性QNB结合增加。Scatchard分析显示，IM应激使隔区、海马以及脑桥+延髓中m-Ch受体的亲和力增加，但未改变结合位点的最大数量（Bmax）。在纹状体中，特异性QNB结合增加是由于Bmax增加和解离常数（Kd）降低所致。本研究提示，IM应激可能由于隔区、纹状体、海马以及脑桥+延髓中突触前胆碱能活性降低而诱导突触后m-Ch受体超敏。由于纹状体和脑桥+延髓中的m-Ch受体受IM应激影响，因此必须在这些区域以及隔区、海马和大脑皮层的应激情况下对m-Ch神经系统进行进一步研究。
