Editors' ChoiceNeuroscience

The Ups and Downs of Neural Activity

Science's STKE  06 Jul 2004:
Vol. 2004, Issue 240, pp. tw244-TW244
DOI: 10.1126/stke.2402004TW244

Neurons function through changes in membrane potential that are induced by transient openings and closings of ion-selective channels (gated either by voltage or by neurotransmitters). The various ions, primarily K+, Na+, and Ca2+, move passively, down their electrochemical gradients, and transporting these ions back whence they came requires energy. Kasischke et al. (see the Perspective by Pellerin and Magistretti) use two-photon imaging of the reduced form of nicotinamide adenine dinucleotide (NADH) to examine the spatial and temporal events during neuronal activity. An initial consumption of NADH in dendrites caused by oxidative metabolism in mitochondria is followed by glycolytic (nonoxidative) metabolism in astrocytes; the latter process generates lactate, which is shuttled out of the astrocyte and into the neuron, where it can then be "burned" within the mitochondria.

K. A. Kasischke, H. D. Vishwasrao, P. J. Fisher, W. R. Zipfel, W. W. Webb, Neural activity triggers neuronal oxidative metabolism followed by astrocytic glycolysis. Science 305, 99-103 (2004). [Abstract] [Full Text]

L. Pellerin, P. J. Magistretti, Let there be (NADH) light. Science 305, 50-52 (2004). [Summary] [Full Text]