Fig. 4.

Astrocyte Ca²⁺ wave propagation was unaffected by injection of BoNT/B. A,Mechanically induced Ca²⁺ wave recorded in astrocytes loaded with the Ca²⁺ indicator fluo-4 in control conditions. Panels show images in pseudocolor mode representing intensity of fluo-4 emission, taken before, during, and after mechanical stimulation, at the times indicated. Zero time corresponds to the time of astrocyte stimulation. Mechanical stimulation increases intracellular Ca²⁺ in the injected cell as well as in neighboring non-stimulated astrocytes.B, Stimulation of a single astrocyte microinjected with fluoro-ruby and BoNT/B (left panel) increases the intracellular Ca²⁺ in the injected cell as well as in neighboring unstimulated astrocytes. Right panels show pseudocolor images representing intensity of fluo-4 emission at the times indicated in A. Zero time corresponds to the time of astrocyte stimulation. C, As in B but with a single astrocyte microinjected with fluoro-ruby, BoNT/B, and BAPTA (left panel). Mechanical stimulation of the injected cell did not change the fluorescent emission of fluo-4 in either the stimulated or neighboring astrocytes (right panels).