Development of Voltage-gated Ion Channels in Amphibian Muscle

穆迪离子通道是一种蛋白质，介导带电分子穿过细胞膜的运动，因此负责产生神经和肌肉细胞使用的电信号。神经和肌肉兴奋性的发展受胚胎发生期间离子通道数量的复杂变化所支配。现在很清楚，在许多细胞中，早期发育阶段的离子通道的类型和性质与成熟状态的离子通道非常不同。这些差异反映了电活动的发育功能，这种功能与成熟细胞中电信号的后期作用不同。通过测量存在于不同发育阶段的功能离子通道。我们可以识别出特定通道可能产生自发电活动的关键时期，然后确定这种活动是否对以后的发育真的很重要。由于在开发过程中通道属性的变化可能变化很快，这些关键时期可能很短，通常只有几个小时长。在许多细胞中，它们可以在胚胎中识别细胞之前发生。因此，为了了解离子通道发育模式的生物学功能，有必要在胚胎发生的早期识别细胞，并在广泛的阶段测量离子通道的类型和特性。该项目使用电生理记录技术来测量肌肉发育不同阶段离子通道的特性，并使用分子技术来改变肌肉发育的具体情况。这将使我们能够准确地确定电活动是如何影响发育的。在一个可获得的实验系统（如青蛙肌肉）中获得的结果可以应用于哺乳动物大脑的发育，在哺乳动物大脑中，已知电活动通常由耳早期感觉经验介导，在确保正常认知发育中起着重要作用。

9514624 Moody Ion channels are proteins that mediate the movement of charged molecules across cell membranes, and thus are responsible for generating the electrical signals used by nerve and muscle cells. The development of excitability in nerve and muscle is governed by complex changes in the populations of ion channels that occur during embryogenesis. It is now clear that in many cells the types and properties of ion channels at early stages of development are very different from those in the mature state. These differences reflect a developmental function for electrical activity, a function that is distinct from the later roles of electrical signaling in the mature cell. By measuring the functional ion channels that are present at different stages of development. we can identify critical periods during which the particular channels present are likely to create spontaneous electrical activity, and then to determine whether that activity is in fact important for later development. Because changes in channel properties during development can be vary rapid, these critical periods can be short, often only a few hours long. In many cells, they can occur before it is possible to identify the cell in the embryo. To understand the biological function of the patterns of ion channel development, therefore, it is necessary to identify cells as early in embryogenesis as possible and to measure the types and properties of ion channels present over a wide range of stages. This project uses electrophysiological recording techniques to measure the properties of ion channels at various stages in the development of a muscle, and molecular techniques to make specific changes in that developmental profile. This will allow determining exactly how electrical activity is influencing development. The results obtained in an accessible experimental system such as frog muscle can then be applied to the development of the mammalian brain, where it is known that electrical activity, often mediated by ear ly sensory experience, plays a role in assuring normal cognitive development.