1.14 - Contributions of Bipolar Cells to Ganglion Cell Receptive Fields

Abstract

The distribution of sensitivity in a ganglion cell's receptive field is approximately the convolution of the bipolar receptive field with a weighting function that is as wide as the dendritic tree. A large dendritic arbor enlarges the ganglion cell’s receptive field and imposes irregularities in the distribution of sensitivity across this field. A small dendritic arbor allows the bipolar cell to set the size of the ganglion cell receptive field and to smooth the distribution of sensitivity. Stochastic properties of the bipolar cell array, as well as adaptation in this array, contribute to these irregularities. Bipolar cells, by their synaptic receptors and other intrinsic properties, initiate temporal frequency channels. Bipolar cells contribute to information encoding by the ganglion cell’s spike train by releasing glutamate in bursts and with good temporal accuracy.