Pharmacological mechanisms underlying the switching from the large-scale depolarization wave to segregated activity in the mouse CNS.
Pharmacological mechanisms underlying the switching from the large-scale depolarization wave to segregated activity in the mouse CNS.
复制标题
小鼠中枢神经系统从大规模去极化波转变为分离活动的药理学机制。
DOI：
10.1111/j.1460-9568.2012.08040.x
复制
发表时间：
2012
影响因子：
3.4
通讯作者：
K.
中科院分区：
文献类型：
--
作者：
Momose-Sato;Y.;Nakamori;T. and Sato;K.
在神经系统的早期发育过程中，在各种结构中观察到同步活动，并被认为在神经发育中起着重要作用。这种活动的一个最引人注目的例子是鸡和大鼠胚胎中报道的去极化波。在随附的论文中（Momose-Satoet al.，2012），我们通过显示大规模光波证明小鼠胚胎中也存在去极化波，该波显着传播到中枢神经系统，包括脊髓、后脑、小脑、中脑和前脑。在本研究中，我们研究了小鼠去极化波的药理学性质及其发育变化。我们在这里表明，两种类型的开关在药理学特性发生在发展过程中。其中之一是，在发育早期[胚胎日（E）11-12]，去极化波强烈依赖于尼古丁乙酰胆碱受体，但在后期（E13以后）由谷氨酸主导。第二种是γ-氨基丁酸（GABA），它在早期阶段作为去极化波的兴奋性介质，通过E14成为抑制性调节剂。这些变化似乎发生在后脑比在脊髓。此外，我们表明，第二个开关导致网络的同步损失，导致去极化波的消失和分离的活动到离散区域的髓质和脊髓。我们认为，药理学开关是一个可能的机制，潜在的原始相关网络的替代成熟的神经元电路。
During the early development of the nervous system, synchronized activity is observed in a variety of structures, and is considered to play a fundamental role in neural development. One of the most striking examples of such activity is the depolarization wave reported in chick and rat embryos. In the accompanying paper (Momose‐Satoet al., 2012), we have demonstrated that a depolarization wave is also present in the mouse embryo by showing large‐scale optical waves, which spread remarkably over the central nervous system, including the spinal cord, hindbrain, cerebellum, midbrain, and forebrain. In the present study, we examined the pharmacological nature of the mouse depolarization wave and its developmental changes. We show here that two types of switching in pharmacological characteristics occur during development. One is that the depolarization wave is strongly dependent on nicotinic acetylcholine receptors during the early developmental stage [embryonic day (E)11–12], but is dominated by glutamate at the later stage (E13 onwards). The second is that γ‐aminobutyric acid (GABA), which acts as an excitatory mediator of the depolarization wave during the early phase, becomes an inhibitory modulator by E14. These changes seemed to occur earlier in the hindbrain than in the spinal cord. Furthermore, we show that the second switch causes the loss of synchronization over the network, resulting in the disappearance of the depolarization wave and segregation of the activity into discrete regions of the medulla and spinal cord. We suggest that pharmacological switching is a possible mechanism underlying replacement of the primordial correlated network by a mature neuronal circuit.