Figure 5. Effect of dietary NaCl on irregular firing pattern.

A, an example of a current clamp recording of a VP neuron from the high NaCl group exhibiting an irregular firing and its rate metre (10 s binned) of the firing activity when no current was applied. The washing of benzamil from the neurons caused an increase in firing frequency, while re‐application of benzamil caused a decrease. Sections a–d indicate the 30 s time frame where the interspike interval (ISI) joint interval histograms and ISI histograms were obtained in B and C, respectively. B, ISI joint interval histogram. Note the more dispersed dots in the presence of benzamil (a and d) compared to those in the absence of benzamil (b and c), representing a more random distribution of ISIs in the presence of benzamil. C, ISI histograms. The mean ISI + standard deviation along with the coefficient of variation (CV) are indicated in each ISI histogram. Note that the CV is smaller in the absence of benzamil (b and c), indicating less interspike variability. D, the mean ISI did not differ between groups in the absence of benzamil; however, it was significantly longer in neurons from the high NaCl diet group compared to those in the control diet group. E, there was no difference in the CV between groups regardless of the presence of benzamil. The application of benzamil caused a significant increase in the CV in the control diet group. However, the increase in the CV observed in neurons from the high NaCl diet group in response to benzamil was not statistically significant.