Fig. 3

Reduction in 5-HT neuronal excitability in htau mice at 4 months. A Confocal images of biocytin-labeled cells (red) in the DRN overlaid with TPH2 staining (green) indicating that recorded cells were 5-HT neurons. B Schematic of patch clamp recordings in the DRN and representative traces of voltage ramps that were used to compute the rheobase and action potential (AP) firing at the 200 pA current step from resting membrane potential (RMP). Intracellular recordings in 5-HT neurons from 4-month-old male C57BL/6 J and htau +/- mice with histograms indicating C RMP, D Input resistance at RMP, E Rheobase and F Current (0–200 pA)-induced spiking in 250 ms from RMP G Representative voltage ramps and AP-current plot at 200 pA current step from a holding potential of − 70 mV. H Input resistance I Rheobase and J Current induced spiking (0–200 pA) from a holding potential of − 70 mV. Action potential kinetics showing the K 10–90% rise slope, L Maximum decay slope, M Time to maximum decay slope, N Event Frequency, and O Instantaneous frequency at 0–200 pA current steps from the RMP. *p < 0.05