Which type of Bipolar cells do NOT have color opponency?

Diffuse bipolar cells do not possess color opponency, which is a crucial aspect of understanding their function in the visual system. These cells receive input from multiple photoreceptors, particularly in the peripheral retina, and are primarily involved in detecting overall illumination and light intensity rather than colors. The convergence of signals from multiple rods or cones allows diffuse bipolar cells to contribute to the overall brightness of a visual scene, rather than discerning specific color information.

In contrast, other types of bipolar cells, like midget bipolar cells, are involved in color processing. They have a one-to-one relationship with either a single cone or specific types of cones (red or green), allowing them to play a key role in color opponency. S bipolar cells (which are involved with blue cones) also exhibit color opponency. Horizontal cells, while they do interact with bipolar cells and can have a role in color processing through lateral inhibition, are not classified as bipolar cells themselves.

Therefore, the unique characteristic of diffuse bipolar cells is their role in intensity processing without color discrimination, highlighting their importance in the visual pathway that focuses more on brightness than on color differentiation.