opened, close to the peak of the action potential) is an important feature of cell excitability. Interestingly, only BD neurons were hyperexcitable when the sodium-to-potassium ratio was close to 0 (Figure 5e), indicating that another cell-intrinsic property had a role. The capacitance of the ‘hyper’ neurons was larger in the control and LR groups compared with the ‘hypo’ neurons. There was no significant change in the capacitance of the ‘hyper’ NR neurons, strengthening the observation of weaker correlation between excitability and capacitance in the NR group. In contrast, the input conductance was generally not a main feature distinguishing between our ‘hyper’ and ‘hypo’ neurons in our DG neurons. The spike of the ‘hyper’ neurons was narrower, with a larger amplitude in all three groups. The fast AHP was larger for ‘hyper’ neurons, and the threshold was less depolarized (Figures 5h–k). Interestingly, the largest difference in the spike shape was attributed to the fast AHP, with a ~ 3-fold change in the control group from the ‘hypo’ to the ‘hyper’ types and an ~ 2-fold change in the LR and NR groups, indicating that the fast AHP was an important determinant of cell hyperexcitability. This lower change in fast AHP in
