Possible Mechanism of Dual-Peak Response in Retinal Ganglion Cells: A Computational Study

It has been observed that a subpopulation of ganglion cells in the chicken retinas responds to repetitive light flashes with a particular dual-peak response. The dual-peak response includes two successive phases: a peak in firing rate occurring shortly after the onset and/or offset of the light flash and another peak in firing rate occurring following the first one with a short interval where the firing rate is quite low. A computational retina model is developed to investigate the origination of the dual-peak response. For simplicity, only a single representative of each neuron type is modeled because of the spatially homogeneous light stimulation we used. Computation results indicate that the fast transient amacrine cell and the slow transient amacrine cell are key neurons for the reproduction of the dual-peak response. The dual-peak response may results from a delayed inhibitory input to a sustained ganglion cell that splits its response into two distinct parts. Besides the dual-peak response, other normal response types of ganglion cell also can be reproduced by the retina model.