Figure 6.

Extracellular K⁺ accumulation during OGD partially account for Bergmann cell depolarization. (A) Extracellular K⁺ concentration is measured through an ion-sensitive microelectrode placed in the molecular layer. Maximal values of [K⁺]_e variations recorded during OGD are reported in the plot (n = 22). (B) An example of simultaneous recordings of [K⁺]_e changes and Bergmann glia membrane potential during OGD (top). Bottom: during the first 10 min of OGD protocol, the membrane potential and [K⁺]_e increase concomitantly revealing high degree of correlation (n = 7) while after this time, [K⁺]_e decreases and membrane depolarization increases further. The P value for the histogram data analysis is *P = 0.02, Wilcoxon Signed-rank test. (C) Mean currents recorded in control (n = 19) and in the presence of 5 mM Ba²⁺ and 10 mM TEA (n = 8). (D) These K⁺ channel inhibitors significantly reduce the electrical charge of Bergmann glia I_OGD (*P = 0.0002).