Figure 4.

Similar sensitivities of the tonic currents recorded in dentate granule cells of control and pilocarpine-treated mice to the benzodiazepine DZ. A, The two raw traces originate from a granule cell each recorded in slices obtained from a control (left) and a pilocarpine-treated (right) mouse, respectively. The horizontal bars indicate the perfusion of the drugs. Note the increase in tonic current in both the control and the pilocarpine-treated cells after perfusion of 1 μm DZ. B, Paired plots of the tonic currents before and after the perfusion of DZ in control and pilocarpine-treated (Pilo) mice. The effect of DZ was significant in both the control (p = 0.003, paired t test; from 19.7 ± 4.9 to 30.4 ± 7.0 pA in DZ; n = 7) and pilocarpine-treated mice (p = 0.02, paired t test; from 20.0 ± 5.7 to 32.7 ± 9.7 pA in DZ; n = 7). Thick lines and symbols indicate mean ± SEM. C, As shown in the box plots, the effect of DZ was to increase the tonic current by 61.2 ± 9.4% in control granule cells, which was not significantly different (p > 0.5; unpaired t test) from its effect on granule cells of pilocarpine-treated mice (59.4 ± 5.0%). The notations of the box plots are as described in Figure 2. D, The linear slope analysis of the tonic current (I _tonic) values before and after DZ treatment also shows a significant effect in both control (slope, 1.51) and pilocarpine-treated mice (slope, 1.65). This graph also indicates that the effect of DZ was independent from the original magnitude of the tonic current.