Ionic current model of bipolar cells in the lower vertebrate retina.

We propose an ionic current model of bipolar cells based on the published experimental data. Five types of ionic currents identified in bipolar cell bodies, Ih, IKv, IA, ICa and IK(Ca) were described by a mathematical formulation similar to the Hodgkin and Huxley (Journal of Physiology, 117, 500-544, 1952) equations. The model parameters were estimated from the voltage clamp data. In simulation, we demonstrate that the present model reproduces not only the voltage clamp responses but also the current clamp responses of the bipolar cells. As a result, the model provides a better understanding of the functional role of the ionic currents in bipolar cells in generating the electrical responses.