Resistor/Capacitor
Single Compartment Model
This board is a set of six single-compartment circuits, each representing a single cell with a transmembrane resistance Rm and capacitance Cm. Increasing cell size (1x, 3.16x, 10x) is modeled by appropriately decreasing Rm (1x, .1x, .01x) and increasing Cm (1x, 10x, 100x). Recording access to each cell is provided by a pair of simple machine screw posts - intracellular (red) and extracellular (black).
As described in Laboratory #15 of the BIO325 manual, this board is used to model electrical synapses between two cells by shorting the two extracellular posts and clipping a suitable-sized resistor across the two intracellular posts. By connecting different-sized cells students model rectifying properties of electrical synapses. They also investigate how large cells (e.g. command neurons) can effectively drive smaller cells and how a large cell electrically coupled to a smaller cell can sink current and pin the membrane potential of the smaller cell.
Printouts of the results of using this model as described in laboratory #15 are available online in a poster (PowerPoint format) or upon request from brhoades@wesleyancollege.edu .