Figure 5.
Effect of glutamate/K+ on astrocytic cell volume. (A) Fluorescence was measured in a calcein-loaded cell during addition of 50 μM glutamate/12 mM K+, followed by a solution in which NaCl had been reduced to make the solution 30% hypotonic (hypo). Relative calcein concentration was calculated from calcein fluorescence using the response to hypotonicity as a calibration factor. (B) The initial time course of the response to glutamate/K+ shown in A (calcein) is plotted together with an example of relative decrease in glucose concentration elicited by K+ (glucose, same data as shown in Figure 4A). (C) Initial rates of decrease are given for a series of experiments with glutamate/K+ for glucose (n = 25 cells in five experiments) and calcein (n = 20 cells in three experiments), *p < 0.05.