Locomotion Induces Fundamentally Different Patterns of Ca2+ Signaling in Astrocytes and Neurons.

A modest literature links the onset of locomotion with increased intracellular calcium (Ca 2 + ) in neurons and astrocytes of the sensory and motor cortex, but a formal comparison of Ca 2 + responses in the two cell types has been lacking. The new study by Fedotova et al. 1 systematically compared Ca 2 + activity induced by locomotion in neurons and astrocytes of awake, behaving mice. A main strength of this study lies in the detailed analysis of Ca 2 + dynamics for the two cell types, in consideration of the coupled activity of neurons and astrocytes during spontaneous locomotion. The authors used recombinant adeno-associated viral (AAV) vectors to express the genetically encoded Ca 2 + sensor GCaMP6f selecti v el y in either astrocytes or excitator y neur ons (AA V5-gfaABC1D-cyto-GCaMP6f or AA V2/9-CamKII-GCaMP6f, r especti v el y) in the somatosensor y cortex. The mice were first trained to accommodate head-fixation to a mobile home cage device mounted on a microscope stage, with detection of locomotion onset by tr ac king softw