FIG. 2.

Ca²⁺ response to shear pulses of different amplitudes and durations in astrocytes. (A and B) Fluorescence images of Fluo-4-loaded astrocytes subjected to a narrow shear pulse (10 ms duration and 2 ms rise time) of 23 (A) and 11.5 dyn/cm² (B). Yellow arrows indicate flow direction. (C and D) Time-dependent changes in Ca²⁺ intensity from selected cells in (A) and (B), respectively. (E) Ca²⁺ responses to a pulse of lower amplitude (11.5 dyn/cm²), but with longer duration (1000 ms), showing that duration of the pulse affects the responses. (F and G) Statistics of peak Ca²⁺ intensity with pulses of different amplitude and duration (n=30 for each condition) and corresponding fitting curves using Equation 1. (H) Profile of stimulus thresholds (amplitude and duration), showing the lowest threshold for Ca²⁺ response is 11.5 dyn/cm² for 10 ms. Scale bar represents 100 μm. Color image is available online at www.liebertpub.com/neu