An integrated energy plan for activated neurons.

This Editorial highlights an ingenious study by Li and Freeman published in this issue of J. Neurochem. Accurately knowing the brain extracellular levels of the two main substrates, that is, glucose and lactate, while a well-controlled and graded-stimulus is applied, might be extremely useful to finely understand how these substrates are produced and used. To that end, the authors have designed a new approach that consists to record at the same time (100 ms resolution) extracellular glucose and lactate concentrations using electrochemical sensing microelectrodes equally distant from a microelectrode that registers the multicellular activity in response to light-dependent stimuli (contrast levels from 10% to 80%). While this approach does, however, not evaluate the metabolic coupling between astrocytes and neurons, it proposes a new design which combined with molecular strategies specifically toward the glial or neuronal compartments will certainly help to demonstrate new distinctive features of this interesting question.