Question

In my teachers slides, it says light hitting the center of the retinal receptive field can either increase or decrease the number of impulses fired Is this or because it depends on whether the light hits a photoreceptor connected to an on or an off bipolar cell?

Answer 1

Light hitting the center of the retinal receptive field can either increase or decrease the number of impulses fired depending on whether it hits a photoreceptor connected to an on or an off bipolar cell.

Step-by-step explanation:

Light hitting the center of the retinal receptive field can either increase or decrease the number of impulses fired. This depends on whether the light hits a photoreceptor connected to an on or an off bipolar cell. In the absence of light, the bipolar neurons that connect rods and cones to ganglion cells are continuously inhibited by the rods and cones. When light hits a photoreceptor connected to an on bipolar cell, it hyperpolarizes the photoreceptor and removes the inhibition, leading to an increase in the firing of the bipolar cell and ultimately the ganglion cell. On the other hand, when light hits a photoreceptor connected to an off bipolar cell, it hyperpolarizes the photoreceptor and removes the inhibition, leading to a decrease in the firing of the bipolar cell and ultimately the ganglion cell.