Mochida Hiraku, Sato Katsushige, Momose-Sato Yoko
Department of Psychiatry, Graduate School and Faculty of Medicine, Kobe University, Kobe, Japan.
Eur J Neurosci. 2009 Jan;29(1):14-30. doi: 10.1111/j.1460-9568.2008.06569.x. Epub 2008 Dec 12.
Widely propagating correlated neuronal activity is a hallmark of the developing nervous system. The activity is usually mediated by multiple transmitters, and the contribution of gap junctions has also been suggested in several systems. In some structures, such as the retina and spinal cord, it has been shown that the dominant transmitter mediating the correlated wave switches from acetylcholine to glutamate during development, although the functional significance of this phenomenon has not been clarified. An important question is whether such a transmitter switch occurs in other systems, especially in the brain. In the present study, we demonstrate that the major transmitter mediating correlated wave activity in the embryonic chick hindbrain changes from acetylcholine/gamma-aminobutyric acid (GABA)/glycine to glutamate/GABA as development proceeds. The results show for the first time that the dominant transmitter switches from acetylcholine to glutamate in a region other than the retina and spinal cord. This finding sheds more light on the role of nicotinic acetylcholine receptors in the generation of correlated wave activity, which is considered to regulate the development of the nervous system.
广泛传播的相关神经元活动是发育中神经系统的一个标志。这种活动通常由多种递质介导，并且在一些系统中也有人提出缝隙连接的作用。在一些结构中，如视网膜和脊髓，已经表明在发育过程中，介导相关波的主要递质从乙酰胆碱转变为谷氨酸，尽管这一现象的功能意义尚未阐明。一个重要的问题是这种递质转换是否发生在其他系统中，尤其是在大脑中。在本研究中，我们证明随着发育的进行，胚胎小鸡后脑中介导相关波活动的主要递质从乙酰胆碱/γ-氨基丁酸（GABA）/甘氨酸转变为谷氨酸/GABA。结果首次表明，在视网膜和脊髓以外的区域，主要递质从乙酰胆碱转变为谷氨酸。这一发现为烟碱型乙酰胆碱受体在相关波活动产生中的作用提供了更多线索，相关波活动被认为对神经系统的发育具有调节作用。
