Fig. 3: In vitro Mg2+-free model whole-cell and extracellular field recordings showing the effect of ZDHHC8 on neuronal hyperexcitability in hippocampal slices.

a Identification of pyramidal neurons in the CA1 region of hippocampal slices. (a) Representative image of the CA1 region; scale bar, 100 µm. (b) Pyramidal neurons (red arrowheads) have a typical soma (cell body) shaped like a teardrop or a rounded pyramid and one projecting axon to which the dendrites bind in a thick band called the stratum radiatum; scale bar, 10 µm. b APs and PDSs of a pyramidal neuron triggered by the omission of Mg²⁺ from the ACSF by whole-cell patch-clamp recordings (holding the resting membrane potential constant) in rAAV-treated and control mice. Top: trace of a cell with spontaneous APs. Bottom: trace of a cell with PDSs. c Quantification of the mean spontaneous firing frequency (n = 4 mice per group). d, e Quantification of the frequency of PDSs (d) and the average number of APs in PDSs (e) (n = 4 mice per group). f–i Epileptiform-like activity elicited in hippocampal slices by removing extracellular Mg²⁺ and adding 8.5 mM K⁺ to the perfusate in the in vitro model. Representative ictal- (f) and interictal-like (g) epileptiform events elicited in the CA1 region. Average frequencies (events/min) (left) and event durations (right) of ictal-like (h) and interictal-like events (i) (unit: slices, n = 4 mice per group). All data represent the mean ± SEM. Statistical significance (*P < 0.05, **P < 0.01, and ***P < 0.001) was evaluated by one-way ANOVA