大鼠新纹状体神经元中苯二氮䓬受体的异质性分布。

Heterogeneous distribution of benzodiazepine receptors among rat neostriatal neurones.

Munakata M, Nakanishi R, Akaike N

Department of Physiology, Faculty of Medicine, Kyushu University, Fukuoka, Japan.

Br J Pharmacol. 1996 Jun;118(3):820-5. doi: 10.1111/j.1476-5381.1996.tb15473.x.

Abstract

The effects of benzodiazepine receptor (BZR) agonist were investigated in dissociated rat neostriatal neurones by a conventional whole-cell patch recording configuration at room temperature. 2. The dissociated neurones, with a longest somatic diameter of larger than 25 microns, were classified as 'large neurones', while those having soma measuring less than 15 microns were described as 'small neurones'. Large neurones were intensely positive for acetylcholinesterase staining, whereas the small ones were not. 3. CL218,872 enhanced the GABA response in both the large and small neurones with similar EC50S. However, the potentiation efficacy of CL218,872 in large neurones was larger than that of small ones. 4. Zolpidem also potentiated the GABA response in both neuronal populations with similar EC50S. This compound also enhanced the GABA response more strongly in large neurones than in small ones. 5. Zopiclone exerted a prominent potentiation in large neurones, although no difference was seen in the EC50S in the large and small neurones. 6. It was concluded that the BZR in large neurones had a different pharmacological property from that in small ones and that the BZR agonists showed a prominent difference, not in EC50, but in the potentiation efficacy between these neuronal populations.

摘要

在室温下，采用传统的全细胞膜片钳记录模式，研究了苯二氮䓬受体（BZR）激动剂对大鼠新纹状体解离神经元的作用。2. 将最长体细胞直径大于25微米的解离神经元归类为“大神经元”，而体细胞直径小于15微米的则描述为“小神经元”。大神经元乙酰胆碱酯酶染色呈强阳性，而小神经元则无此现象。3. CL218,872在大、小神经元中均增强GABA反应，其半数有效浓度（EC50）相似。然而，CL218,872在大神经元中的增强效力大于小神经元。4. 唑吡坦在两个神经元群体中也增强GABA反应，其EC50相似。该化合物在大神经元中增强GABA反应的作用也比小神经元更强。5. 佐匹克隆在大神经元中产生显著的增强作用，尽管在大、小神经元的EC50上未见差异。6. 得出的结论是，大神经元中的BZR与小神经元中的BZR具有不同的药理学特性，并且BZR激动剂在这些神经元群体之间的差异不在于EC50，而在于增强效力。