The effect of shear forces on the response of cells to an

∼11 atm peak pressure simulated blast. (A) Sequential fluo-4 calcium imaging of a dissociated primary human fetal CNS cell culture without shear (380 µl well fluid volume); the blast occurred at time 100 seconds. (B) Sequential fluo-4 calcium imaging of the same cells as in Figure 3A with shear (150 µl well fluid volume) using the same blast parameters; the blast occurred at time 100 seconds. (C) ΔF/F in time of the cells shown in Figures A and B for 10 minutes before, during, and after the blast. (D) Normalized response of two cells shown in Figure B, panel 1, indicating that the calcium response does not occur simultaneously in cells but sequentially; time to peak response is offset by ∼30 seconds in this example and is consistent with propagation (see Video S4). (E) Integrated Ca2+ Response, integral of ΔF/F over time following the blast, without and with shear forces in the same well, for n = 6 pair-matched experiments (11 atm; 10 atm above ambient pressure). The first blast was without shear forces. The response to a lethal peak pressure of 15 atm (14 atm above ambient pressure) with no shear forces is also shown (n = 10) (F) Correlation (r2 = 0.99) between Integrated Ca2+ Response following a 11 atm peak pressure blast and well fluid volume for the 3 volume conditions evaluated; 150–200, 250–300, and 380 µl with n = 14, 7 and 25, respectively. Fluid volume and Ca2+ Response error bars are the range and SEM, respectively.