Figure 8.

Block of the negative E_gly shift by H₂DIDS. A, Simultaneously obtained SNARF signal and E_gly from one cell are shown for control condition (Ai) and in100 μm H₂DIDS (Aii) along with the V_m trace of Ca²⁺ spiking. Thick bars indicate periods of 8 s Ca²⁺ spiking. Arrowheads indicate the time of 2 mm glycine puff. The number of evoked Ca²⁺ spikes is shown in parenthesis. The bias currents during the 8 s current injection were −80 pA and −55 pA for i and ii, respectively. B, Another example showing the difference in magnitude and time course of pH_i change between the control condition and in H₂DIDS. The period of 8 s Ca²⁺ spiking evoked with 70 pA is bound by a rectangle. Numbers of evoked Ca²⁺ spikes are shown in parenthesis. The arrow indicates the time of peak acidification in H₂DIDS. C, Plot of peak acidification (in SNARF's ΔF/F) against the peak negative E_gly shift in control condition and the peak positive E_gly shift in H₂DIDS. Five cases (pairs) from different cells are shown. The same depolarizing current injection was used for control and H₂DIDS conditions in each of the five cases, but the amount ranged from 70 to 300 pA in different cells. The average of peak negative E_gly shifts in controls is −2.6 ± 1.1 mV, and that of peak positive shifts in H₂DIDS is 0.9 ± 0.4 mV for the five cases in the plot.