Somato-dendritic nicotinic receptor responses recorded in vitro from the medial septal diagonal band complex of the rodent
Somato-dendritic nicotinic receptor responses recorded in vitro from the medial septal diagonal band complex of the rodent
复制标题
DOI：
10.1113/jphysiol.2004.070300
复制
发表时间：
2005-01-01
影响因子：
5.5
通讯作者：
Halasy, K
中科院分区：
文献类型：
--
作者：
Henderson, Z;Boros, A;Halasy, K
内侧隔斜角带区（MS/DB）由GABA能和胆碱能神经元组成，在海马θ节律的产生和调节中起重要作用。为了了解胆碱能神经元可能在这一活动中发挥的作用，我们试图确定是否可以检测到突触后烟碱受体反应的啮齿动物MS/DB切片上的乙酰胆碱（ACh）。神经元根据以前的标准，在电生理学上被表征为GABA能神经元和胆碱能神经元。MS/SB神经元对ACh的反应为快去极化（1.5- 2.5s）、快超极化（3- 4s）和慢去极化（20-30 s）的不同组合，后两者可被阿托品阻断。快速去极化部分或不阻断镉和低钙，河豚毒素，和其他离子型受体的拮抗剂，并与25 μ M美加明拮抗。对反应的药理学研究表明，α 7 * 尼古丁受体类型与胆碱能神经元和10%的GABA能神经元相关，而非α 7 * 尼古丁受体亚型与50%的GABA能神经元相关。然而，诱发和自发突触后反应的药理学解剖，没有提供证据的MS/DB中的突触烟碱受体传递。它的结论是，烟碱受体，虽然普遍的体细胞和/或树突状细胞膜室的神经元在MS/DB，突触外的网站，他们大概发挥神经调节作用。胆碱能神经元上α 7 * 烟碱受体的存在也可能使这些细胞特别容易在阿尔茨海默病中变性。
The medial septal diagonal band area (MS/DB), made up of GABAergic and cholinergic neurones, plays an essential role in the generation and modulation of the hippocampal theta rhythm. To understand the part that the cholinergic neurones might play in this activity, we sought to determine whether postsynaptic nicotinic receptor responses can be detected in slices of the rodent MS/DB by puffing on acetylcholine (ACh). Neurones were characterized electrophysiologically into GABAergic and cholinergic neurones according to previous criteria. Responses of the MS/SB neurones to ACh were various combinations of fast depolarizations (1.5-2.5 s), fast hyperpolarizations (3-4 s) and slow depolarizations (20-30 s), the latter two being blocked by atropine. The fast depolarizations were partially or not blocked with cadmium and low calcium, tetrodotoxin, and antagonists of other ionotropic receptors, and were antagonized with 25 muM mecamylamine. Pharmacological investigation of the responses showed that the alpha7* nicotinic receptor type is associated with cholinergic neurones and 10% of the GABAergic neurones, and that nonalpha7* nicotinic receptor subtypes are associated with 50% of the GABAergic neurones. Pharmacological dissection of evoked and spontaneous postsynaptic responses, however, did not provide evidence for synaptic nicotinic receptor transmission in the MS/DB. It was concluded that nicotinic receptors, although prevalent on the somatic and/or dendritic membrane compartments of neurones in the MS/DB, are on extrasynaptic sites where they presumably play a neuromodulatory role. The presence of alpha7* nicotinic receptors on cholinergic neurones may also render these cells specifically vulnerable to degeneration in Alzheimer's disease.