Figure 5. Ca²⁺-dependent and independent change in E_gly.

(A,B) Data from one cell comparing glycine responses and E_gly measurements in control condition (A) with those in zero-Ca²⁺ (B). Time 0 is the moment the 8-sec depolarizing current injection terminated. (Ai) After 56 high-threshold Ca²⁺ spikes induced with a 220 pA injection, the glycine response shifted negative. (Aii) The E_gly series measured along with the V_m recording in (Ai) is shown (?) with two other series obtained with different amount of current injections. The negative E_gly shifts peaked at 8.5 sec. HTSs: high threshold spikes. (Bi,ii) The V_m and E_gly series in zero-Ca²⁺ (replaced with Mg²⁺) are displayed in the same way as in (A). After a depolarization in zero-Ca²⁺, no negative shift but a positive shift in E_gly occurred. Bias current was −40 pA in (Ai) and −55 pA in (Bi). (C) Bar graphs showing the peak change in E_gly after an 8-sec current injection (amount in pA indicated above each bar) in control condition and in zero-Ca²⁺, from 6 cells. Number of Ca²⁺ spikes evoked is shown in parentheses under each bar belonging to control conditions. All data were obtained in TTX.