细胞兴奋性.神经系统的基因表达与调控-神经科学百科全书-7

本书特色

《神经科学百科全书:细胞兴奋性、神经系统的基因表达与调控(导读版)(影印版)》由科学出版社出版。

内容简介

《神经科学百科全书》原书篇幅巨大，为所有神经科学百科全书之首。由来自世界各地的2400多位专家撰稿人合力打造，覆盖了神经科学全部主要领域。书中每个词条在收入书中之前均经过顾问委员会的同行评议，词条中均含有词汇表、引言、参考文献和丰富的交叉参考内容。

节选

相关资料

插图：Voltage-gated potassium channels have K+-selectivepores that are opened by membrane depolarization.This opening allows the movement of K+ ions acrossthe plasma membrane and the generation of K+ cur-rents that tend to repolarize the membrane towardthe equilibrium potential for K+ （EK）. Voltage-gatedpotassium channels contribute widely to the electricalproperties of neurons. They influence subthresholdproperties, including the resting potential and mem-brane resistance. They influence the amplitude andfrequency of subthreshold oscillations, the responsive-ness of the cell to synaptic inputs, and the probabilityof spike generation. They help shape postsynapticpotentials, and they are the main determinants of therepolarization of the action potential governing spikeshape and frequency. Their voltage-dependent activityensures a non-ohmic current-voltage relationship,which thereby enables the channels to contribute tothe nonlinear properties of neurons. Voltage-gatedpotassium channels have similar functions in otherexcitable cells, including all varieties of muscle. In non-excitable cells, they contribute to the resting potentialand to the regulation of Ca2+ entry and secretion. Voltage-gated K+ channels differ dramatically intheir kinetic and voltage-dependent properties aswell as their cellular and subcellular distributions.This diversity is a main contributor to the varied elec-trical properties of neuronal populations throughoutthe nervous system. Thus, understanding the input-output relationship of neuronal elements demands thecontinued effort to study the properties and localiza-tion of these channels and analyze their physiologicalroles in native membranes.