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

Directional selectivity in tangential cells (Tan1) of crayfish optic lobe i s simulated with a single compartment cellular model. The simulation is bas ed upon spatiotemporal asymmetric receptive subfields and antagonistic acti ons of acetylcholine (ACh) and a delayed GABA signal on Tan1 chloride chann els. The interaction is modeled as competitive inhibition of ACh receptor b inding. Alternative implementations assume either convergence of columnar i nputs to common dendritic sites or discrete interactions at retinotopically distinct sites on the Tan1 dendrite. The "pooled" or convergent model is m ore directional but the discrete model is probably a better representation of the anatomy, (C) 1999 Elsevier Science B.V. All rights reserved.