Volume 9 Supplement 1
Voltage attenuation in reconstructed type-identified motor neurons as a constraint for reduced models
© Kim et al; licensee BioMed Central Ltd. 2008
Published: 11 July 2008
Attenuation of voltage in dendrites depends on the direction of propagation : Direction Dependent Voltage Attenuation (DDVA). This study's objectives were to: 1) determine whether DDVA differed for motor neurons of different types (i.e. slow – fast), and 2) derive the cable parameters for reduced models that satisfy DDVA for the heteronymous properties of motor neurons in a pool.
The morphologies of six type-identified cat spinal motor neurons were downloaded from a public database  and imported into the NEURON simulation environment. Passive parameters were set to experimentally determined values from these same cells . DDVA was characterized by calculating the voltage attenuation between the soma and all sites on the dendrites in both directions.
Type-specific dendritic morphology had no obvious effect on DDVA. DDVA in spinal motor neurons was fully characterized by input resistance at the soma. The two-compartment models are the first to analytically solve for reduced cable parameters based on reconstructed neurons. This solution has important implications for the bistable firing behavior in these cells.
Work supported by grants from NSERC and AHFMR.
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