Energy-Efficient Action Potentials in Hippocampal Mossy Fibers

作者：Henrik Alle, Arnd Roth, Jörg R. P. Geiger · 发表于：Science · 年份：2009 · DOI：10.1126/science.1174331 · 被引用次数：441 · 研究领域：Neural dynamics and brain function、Neuroscience and Neuropharmacology Research、Neuroscience and Neural Engineering

Action potentials in nonmyelinated axons are considered to contribute substantially to activity-dependent brain metabolism. Here we show that fast Na+ current decay and delayed K+ current onset during action potentials in nonmyelinated mossy fibers of the rat hippocampus minimize the overlap of their respective ion fluxes. This results in total Na+ influx and associated energy demand per action potential of only 1.3 times the theoretical minimum, in contrast to the factor of 4 used in previous energy budget calculations for neural activity. Analysis of ionic conductance parameters revealed that the properties of Na+ and K+ channels are matched to make axonal action potentials energy-efficient, minimizing their contribution to activity-dependent metabolism.