Evaluation of a model of the cochlear neural membrane. II: Comparison of model and physiological measures of membrane properties measured in responseto intrameatal electrical stimulation
La. Cartee, Evaluation of a model of the cochlear neural membrane. II: Comparison of model and physiological measures of membrane properties measured in responseto intrameatal electrical stimulation, HEARING RES, 146(1-2), 2000, pp. 153-166
This study examines existing equation sets describing neural membrane ionic
currents, such as the Hodgkin-Huxley (1952) equations, used to define the
membrane currents in a numerical model of the auditory neuron and determine
s their adequacy for modeling the summation and refraction properties of au
ditory neurons in response to electrical stimulation. Specifically, the sum
mation and refraction time constants of each equation set are compared to p
hysiological measures of these time constants. Since previous studies have
shown the cell body and peripheral process of the auditory neuron may influ
ence the measurement of neural time constants, the physiological time const
ants used for comparison are those which were recorded using intrameatal el
ectrical stimulation. The intrameatal electrode should stimulate the neuron
in an area where the axon has a uniform geometry. Accordingly, the neural
model used to duplicate this experiment was also of uniform geometry. Of th
e membrane equation sets evaluated, none was clearly superior for modeling
both the refraction and summation properties of the auditory neuron, though
some equation sets were capable of accurately modeling either the refracti
on or the summation properties, provided operating temperatures were adjust
ed to provide appropriate kinetics. (C) 2000 Elsevier Science B.V. All righ
ts reserved.