Figure 6.
Wash out of extracellular HCO3− reduces back-propagation of antidromic APs. A, Antidromic ACs were elicited by local axon stimulation (80 μs pulse width, ∼250 μm away from the soma) of visually identified CA3 PCs. B, E, Trains of stimuli (5 stimuli, 50 Hz, asterisks) evoked antidromic ACs recorded with 0 mm [HCO3−]p and 26 mm [HCO3−]o and stimulus intensities were adjusted so that the pAC ≈ 0.5 over 10 successive stimulus trains (raster plot, E). C, F, Wash out of [HCO3−]o significantly reduced the pAC, illustrated with raster plots of ACs during 10 successive stimulus trains after 10–12 min (n = 5, p = 0.009, one-way ANOVA, Dunnet's test). D, G, The pAC recovered upon subsequent XE 991 wash in (n = 3, p = 0.143, one-way ANOVA, Dunnet's test). H, Individual recordings indicated with gray lines, p = 0.001, one-way ANOVA. Black lines represent mean pAC ± SEM.