Resistor-Ladder Cable Properties Model
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This model was derived directly from the circuit board described in Laboratory #1of Wyttenbach, R.A., Johnson, B.R., Hoy, R.R.  (1999). Crawdad: A CD-ROM Lab Manual for Neurophysiology (Student Version). Sinauer.  It models a cylindrical axon with passive membrane as a series of identical compartments, each represented by a high transmembrane resistance Rm = 1kW, and each separated from its neighbors by moderate intracellular longitudinal resistances Ri = 100W and small extracellular longitudinal resistances Ro=10W.  Recording access to each compartment is provided by a pair of simple machine screw posts - intracellular (red) and extracellular (black).     As described in Crawdad Lab #1 and Laboratory #8 of the BIO325 manual, this model is used with a constant DC voltage (supplied by a 9V battery) to study spatial decay of input signal amplitude with distance, as well as the differences between intracellular (transmembrane) and extracellular recording perspectives.   The results of using this model as described in laboratory #8 are detailed in the Crawdad manual and are available upon request from brhoades@wesleyancollege.edu .