A Relationship between PSP amplitudes and membrane potential. There is a clear linear trend in stellate neurons near threshold under control conditions (i) but not in TTX (ii) or in pyramidal neurons (iii). For stellate neurons in ZD7288 (iv), the effect is reduced, but largely maintained. B Summary plots for the percent modulation of excitatory (orange) and inhibitory (blue) PSP amplitude per mV depolarization under the various conditions described. Stellates cells near threshold are significantly different (in both excitatory and inhibitory) from all other conditions (ANOVA with Tukey test for means, p < 10−2) except where otherwise noted. In ZD7288 trials, stellate cells near threshold were significantly different (ANOVA with Tukey test for means, p < 10−2) from stellates at rest, for both excitatory and inhibitory trials.