Chunk #50 — RESULTS — Hyperexcitability is reversed by chronic Li treatment of LR DG-like neurons but not of NR neurons, and Li treatment reduces cell capacitance in both LR and NR neurons
neurons with a broader spike had shifted to the ‘hypo’ group (Supplementary Figure 4m and n). The threshold was less depolarized in the ‘hyper’ neurons of the LR group (5 mV less depolarized, P = 0.025). In the NR group, the effect was in the ‘hypo’ group (4.9 mV less depolarized after Li treatment, P = 0.037). While it is hard to draw clear conclusions from these data—as we can only look at Li-untreated and -treated cells but not at the same cell with/without Li treatment and we therefore do not know if there was an exchange of cells between the ‘hyper’ and ‘hypo’ groups—there are some strong hypotheses that can be proposed. It appears that Li shifts many more ‘hyper’ state cells to the ‘hypo’ state in the LR group, whereas in the NR group the shift seems to be in both directions, resulting in a similar number of cells that are hyperexcitable after Li treatment. For both NR and LR neurons, Li generally decreases the fast AHP and broadens the spike but opens the sodium channels at a lower (less depolarized) potential. The final effect depends very much on the initial properties of the cell. For example, in
