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In vivo neural activity of electrosensory pyramidal cells: Biophysical characterization and phenomenological modeling
Fig 2
Comparison of electrophysiological features between intracellular recording of a given ELL pyramidal cell and a model simulation.
(A) Schematic of the model showcasing the two-compartments of the cell: soma and dendrite (left), and highlighting the various ionic currents expressed in each compartment, including fast Na + (
), delayed rectifier K + (
), small-conductance K + (
), NMDA (
) and leak (
) currents in the soma (i = S) and dendrite (i = D). The kinetics of NMDA receptors are governed by a Markov model (see Methods). The schematic of Ca2 + dynamics within the dendritic compartment following the flux-balance model is also shown (right). It displays all fluxes involved in regulating Ca2 + mobilization across plasma and ER membranes in the dendritic compartment. These fluxes include Ca2 + entry through NMDA receptors (
) and IP3 receptors (
), Ca2 + efflux through SERCA (
) and PMCA (
) pumps, and leak across both membranes. (B) Schematic of an action potential with the extracted electrophysiological features (highlighted in pink) for model fitting; that includes from left to right: spike threshold (threshold), midpoint of the upstroke phase (upstrokev), peak amplitudes (peakv), midpoint of the downstroke phase (downstrokev), trough amplitudes (troughv) and amplitude of afterdepolarization potential (adpv). (C) Extracted action potentials (left) and action potential cycles (right) obtained from one recorded trace (5 sec; shaded dark blue) and the average action potential and average action potential cycle of all spikes obtained from a single model simulation overlaid on top (5 sec; light blue). (D) Box plots of electrophysiological features obtained from all action potentials extracted from the experimental recording and model simulation in C. Panels from left to right: thresholdv, upstrokev, peakv, downstrokev, troughv and adpv. Statistical comparisons were performed using two-sample t-tests, Mann–Whitney U tests, and Kolmogorov–Smirnov tests. No significant differences were found for any feature (thresholdv: 
, 
, 
; upstrokev: 
, 
, 
; peakv: 
, 
, 
; downstrokev: 
, 
, 
; troughv: 
, 
, 
; adpv: 
, 
, 
). For adpv estimation, spikes without a detected ADP were omitted.
doi: https://doi.org/10.1371/journal.pcbi.1013711.g002