The model of type II cochlear ganglion cell was based on the immunostaining of the mouse auditory pathway. Specific antibodies were used to map the distribution of voltage-dependent sodium channels along the two unmyelinated axon-like processes of the bipolar ganglion cells. Three distinct hot spots were detected. A high density of sodium channels was present over the entire trajectory of sensory endings beneath the outer hair cells (the most distal portion of the peripheral axon). The other two hot spots were localized in the initial segments of both of the axons that flank the unmyelinated bipolar ganglion cell bodies. A biophysical model indicates that all three hot spots might play important roles in action potential initiation and propagation. For instance, the hot spot in the receptor segment is important for transforming the receptor potentials into a full blown action potential (Supplemental Fig. 1). The hot spots in the two paraganglionic axon initial segments are there to ensure the successful propagation of action potentials from the peripheral to the central axon through the cell body. The Readme.txt file provides step by step instructions on how to recreate Figures 6 and 7 of Hossain et al., 2005 paper.
Model Type: Neuron or other electrically excitable cell
Cell Type(s): Cochlear ganglion cell Type II
Model Concept(s): Action Potential Initiation; Dendritic Action Potentials; Audition
Simulation Environment: NEURON
Implementer(s): Antic, Srdjan [antic at neuron.uchc.edu]
References:
Hossain WA, Antic SD, Yang Y, Rasband MN, Morest DK. (2005). Where is the spike generator of the cochlear nerve? Voltage-gated sodium channels in the mouse cochlea. The Journal of neuroscience : the official journal of the Society for Neuroscience. 25 [PubMed]