Nakajima Yasuko, Nakajima Shigehiro
Department of Anatomy and Cell Biology, College of Medicine, University of Illinois at Chicago, Chicago, Illinois, USA.
Methods Enzymol. 2010;484:613-30. doi: 10.1016/B978-0-12-381298-8.00030-7.
Electrophysiological experiments in our laboratory have led to the discovery that the cholinergic neurons in the nucleus basalis in the rat forebrain possess constitutively active inward rectifier K(+) channels. Unlike cloned inward rectifier K(+) channels, these constitutively active inward rectifier K(+) channels were found to have unique properties, and thus were named "KirNB" (inward rectifier K(+) channels in the nucleus basalis). We found that slow excitatory transmitters, such as orexin (hypocretin) and substance P, suppress the KirNB channel, resulting in neuronal excitation. Furthermore, it was discovered that suppression of KirNB channels by these transmitters is through protein kinase C (PKC). This chapter describes detailed electrophysiological techniques for investigating the effects of orexin and substance P on constitutively active KirNB channels. For this purpose, we also present a method for culturing nucleus basalis cholinergic neurons in which KirNB channels exist. Then, we describe the procedures through which PKC has been determined to mediate inhibition of KirNB channels by orexin and substance P. There are probably many other transmitters which may produce effects on KirNB channels. This chapter will enable researchers to investigate the effects of such transmitters on KirNB channels and their roles in neuronal functions.
我们实验室的电生理实验发现，大鼠前脑基底核中的胆碱能神经元拥有组成型活性内向整流钾通道。与克隆的内向整流钾通道不同，这些组成型活性内向整流钾通道具有独特的特性，因此被命名为“KirNB”（基底核中的内向整流钾通道）。我们发现，慢兴奋性递质，如食欲素（下丘脑泌素）和P物质，会抑制KirNB通道，从而导致神经元兴奋。此外，还发现这些递质对KirNB通道的抑制作用是通过蛋白激酶C（PKC）实现的。本章描述了用于研究食欲素和P物质对组成型活性KirNB通道影响的详细电生理技术。为此，我们还介绍了一种培养存在KirNB通道的基底核胆碱能神经元的方法。然后，我们描述了确定PKC介导食欲素和P物质对KirNB通道抑制作用的过程。可能还有许多其他递质会对KirNB通道产生影响。本章将使研究人员能够研究此类递质对KirNB通道的影响及其在神经元功能中的作用。
