BEHAVIORAL /HORMONAL REGULATION OF EXCITABLE MEMBRANES

我们已经开发了一个模型系统，用于探索动物的物理和社会环境的变化如何导致其可兴奋膜的重塑。硬骨鱼电鱼pinnicaudatus产生一种用于电定位和交流的电波形。电波形的形状和振幅是由离子电导和电器官中可兴奋膜的动力学决定的。波形特性的变化有逐渐的（小时-天）和迅速的（分钟）。这两个时间过程分别与基因组类固醇作用和未知激素的非基因组作用相一致，这些激素作用于修饰电器官的可兴奋膜。我们可以通过在实验室中操纵光线和社会条件来引起鱼的电波形特性的变化。在提议的项目中，我们将确定哪些激素产生了我们在电波形中看到的快速和缓慢的变化，并确定变化波形背后的离子机制。该系统的一个优点是其生物学相关性的范围；我们了解电波形变化的行为意义，因此通过确定细胞和分子机制，我们可以绘制出从社会行为到离子通道和第二信使系统的潜在基因调控的长链连续因果关系。这个项目的一个潜在好处是有可能定位重要的新生物分子，包括性类固醇的膜受体。

We have developed a model system for exploring how changes in an animal's physical and social environment result in the remodeling of its excitable membranes. The teleost electric fish Brachyhypomus pinnicaudatus produces an electric waveform for electrolocation and communication. Shape and amplitude of the electric waveform are determined by ion conductance and kinetics of excitable membranes in the electric organ. Waveform properties change both gradually (hours- days) and quickly (minutes). These two time courses are consistent with genomic steroid action and a non-genomic action respectively of unidentified hormones working to modify the excitable membranes of the electric organ. We can elicit changes in the fish's electric waveform properties by manipulating light and social conditions in the lab. In the project proposed, we shall determine which hormones produce the rapid and slow changes we see in the electric waveform and identify the ionic mechanisms underlying the changing waveform. A strength of this system is the scope of its biological relevance; we understand the behavioral significance of the electric waveform changes, so by determining the cellular and molecular mechanisms, we can draw a long chain of continuous causal connections, from social behavior to the underlying gene regulation of ion channels and 2nd messenger systems. A potential benefit of this project is the possibility of localizing important new biomolecules including membrane receptors for sex steroids.