Probing mechanistic models for the retinogeniculate circuit in cat using drifting gratings

Experiments with drifting gratings are widespread in the study of neurons in the retina and dorsal lateral geniculate nucleus (dLGN). As an alternative to descriptive modeling based on the di!erence-of-Gaussians model, we show how mechanistic models for the retinogeniculate circuitry can be tested against drifting-grating data. As an example of this approach we (i) derive mechanistic expressions for the geniculate contrast gain for X-type relay cells in dLGN for a set of models with direct feedforward excitation and feedforward inhibition via intrageniculate interneurons, and (ii) compare the expressions with example data from the literature. 2001 Elsevier Science B.V. All rights reserved.