A, mean charge of EPSCs mediated by AMPA / kainate receptors at −60 mV evoked by a range of stimuli, normalised to the charge of EPSCs evoked by a 25 ms, −10 mV stimulus in the same paired recording (n= 14–23) versus mean Cm increase, normalised to the Cm increase evoked by a 25 ms, −10 mV stimulus, in axon-severed BCTs (n= 45–94). The dashed line shows a 1:1 ratio. B, as for A, but for EPSCs mediated by AMPA/kainate and NMDA receptors at +40 mV (n= 4–7 for EPSC charge values).