Corrections for space-clamp errors in measured parameters of voltage-dependent conductances in a cylindrical neurite.
The ability to correct parameters of voltage-gated conductances measured under poor spatial control by point voltage clamp could rescue much flawed experimental data. We explore a strategy for correcting errors in experiments that employs a full-trace approach to parameter determination. Simulated soma voltage-clamp runs are made on a model neuron with a single voltage-gated, Hodgkin-Huxley channel type distributed uniformly along an elongate process. Estimates for both kinetic and I(V) parameters are obtained by fitting a form of the Hodgkin-Huxley equations to the complete time course of leak-subtracted current curves. The fitted parameters are used to determine how much correction in each parameter is needed to regenerate the set actually belonging to the channel. Corrections are generated for a range of neurite lengths, conductance densities, and channel characteristics.
Castelfranco
Ann M
AM
Békésy Laboratory of Neurobiology, Pacific Biomedical Research Center, University of Hawaii at Manoa, 1993 East-West Road, Honolulu, HI 96822, USA. castelf@pbrc.hawaii.edu
Hartline
Daniel K
DK
D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D003198:Computer Simulation; D003712:Dendrites / Q000502:physiology*; D004553:Electric Conductivity; D015640:Ion Channel Gating / Q000502:physiology; D007700:Kinetics; D008959:Models, Neurological; D009474:Neurons / Q000166:cytology*; D018408:Patch-Clamp Techniques / Q000379:methods; D013997:Time Factors