Figure 1

Glioma co-culture increases basal [Cl⁻]_i in mouse hippocampal neurons depolarizing E_GABA. (a) Average I–V relation of GABA-activated currents recorded by perforated patch in control (n=24; purple circles) and glioma co-cultured (24 h,1 : 1 ratio; n=18; green circles) neurons (12 DIV); typical traces recorded in control and co-cultured neurons at indicated membrane potentials; (b) Left, distributions of E_GABA in control (purple columns) and co-cultured neurons (green columns; average E_GABA, control −73.9±1.2 mV, co-culture −52.1±1.6 mV; n=124/101, P<0.001 ANOVA); Right, distributions of RMP in control (purple columns) and co-cultured neurons (green columns; average RMP, control −66.6±0.7 mV, co-culture −63.1±0.9 mV; n=124/101, P<0.05 ANOVA); (c) Driving force for GABA (RMP—E_GABA) (control/co-culture as in (b); n=124/101; P<0.001 unpaired t-test); (d) basal neuronal [Cl⁻]_i measured in neurons transfected with Cl-Sensor (control, [Cl⁻]_i=9.1±1.2 mM, purple column n=243; co-cultures, [Cl⁻]_i =16.9±4.1 mM; green column, n=43), and calculated using Nernst equation (control, n=124; co-culture, n=101; P<0.001 unpaired t-test)