Extended Data Fig. 9: Outside-out patch size estimation. Related to Fig. 3.
From: Allometric rules for mammalian cortical layer 5 neuron biophysics
a, Rat dual nucleated patch recordings to test the efficacy of voltage-clamp under nucleated patch configuration. b, Voltage-clamp command action potential waveform (black) and independently observed waveform (grey) without compensation (left) or with series resistance and whole-cell capacitance predicted and compensated >90% and lag <10 µs (right). c, Percentage of command waveform amplitude observed with the independent electrode (n = 4; p = 0.0045, two-sided paired t test, t = 4.41 & 6 df). Pooled data represent mean ± SEM. d, Rat nucleated patch recording with series resistance and whole-cell capacitance predicted and compensated >90% and lag <10 µs. e, Kv currents from the recording in d. f, Rat Kv peak current density computed using the Kv currents and patch surface area (n = 22). Pooled data represent mean ± SEM. g, Rat Kv peak currents in somatic outside-out patch (n = 80). Box plots denote the median and 25–75th percentiles. h, Outside-out patch surface area computed using the mean Kv peak current density in f and the median Kv peak current in g. i-j, Recapitulation of outside-out patch recordings in a compartmental model of rat L5 neuron. i, Model dendritic outside-out patches as spheres of 50 µm2. HCN (top) and Kv (bottom) currents (right) with associated voltage-clamp protocol (left). j, Model Kv currents in somatic outside-out patches. k, Morphology used in the model taken from (https://senselab.med.yale.edu/ModelDB/ShowModel?model=124043#tabs-3). l, Distal dendritic (520 µm from soma) and somatic voltage in response to subthreshold step current injections in the model. m, Somatic and dendritic input resistance as a function of distance from the soma. Fit to experimental rat data in blue taken from Fig. 2d versus model data in black. n, Somatic and dendritic voltage sag as a function of distance from the soma. Fit to experimental rat data in blue taken from Extended Data Fig. 6 versus model data in black.
