Ge Rongjing, Chen Na, Wang Jin-Hui
Department of Physiology, Bengbu Medical College, Anhui, China.
Biochem Biophys Res Commun. 2009 Sep 25;387(3):585-9. doi: 10.1016/j.bbrc.2009.07.066. Epub 2009 Jul 17.
Homeostasis of internal environment and cellular metabolism ensures cells' functions to be stable in living organisms. Cellular homeostasis is believed to be maintained via feedback or feedforward manners. We report a novel mechanism that maintains neuronal homeostasis through coordinating the intrinsic properties of single molecules concurrently. Spike encoding and sodium channel dynamics at cortical neurons were studied by patch-clamp recording. Voltage-gated sodium channels set refractory period and threshold potential toward different directions to stabilize the energetic barrier for firing sequential action potentials. This neuronal homeostasis is not affected by intracellular Ca(2+) signals and membrane potentials. Real-time homeostasis maintains precise and reliable neuronal encoding without any destabilization.
内环境稳态和细胞代谢确保了生物体中细胞功能的稳定。细胞稳态被认为是通过反馈或前馈方式维持的。我们报告了一种通过同时协调单个分子的内在特性来维持神经元稳态的新机制。通过膜片钳记录研究了皮层神经元的动作电位编码和钠通道动力学。电压门控钠通道将不应期和阈电位设置为不同方向,以稳定发放连续动作电位的能量屏障。这种神经元稳态不受细胞内Ca(2+)信号和膜电位的影响。实时稳态维持精确可靠的神经元编码而不会出现任何不稳定。