A cellular model of directionally selective visual motion detection in crayfish tangential cells

Abstract Directional selectivity in tangential cells (Tan1) of crayfish optic lobe is simulated with a single compartment cellular model. The simulation is based upon spatiotemporal asymmetric receptive subfields and antagonistic actions of acetylcholine (ACh) and a delayed GABA signal on Tan1 chloride channels. The interaction is modeled as competitive inhibition of ACh receptor binding. Alternative implementations assume either convergence of columnar inputs to common dendritic sites or discrete interactions at retinotopically distinct sites on the Tan1 dendrite. The “pooled” or convergent model is more directional but the discrete model is probably a better representation of the anatomy.