Final answer:
Photoreceptors are hyperpolarized by light, and ON bipolar cells are less inhibited as they receive less glutamate, being less hyperpolarized. This differs from other sensory systems, where receptors typically depolarize when stimulated, increasing activity to signal a stimulus.
Step-by-step explanation:
Photoreceptors are hyperpolarized by light and release less glutamate. On bipolar cells are inhibited by glutamate, receiving less of it from photoreceptors. Therefore, they are less hyperpolarized and exhibit an increase in voltage.
The relationship between photoreceptors and bipolar cells is primarily different from other sensory receptors and adjacent cells because other sensory receptors typically become depolarized when stimulated, whereas photoreceptors are hyperpolarized by light. In the dark, photoreceptors are depolarized, which inhibits bipolar cells through the release of glutamate. However, exposure to light results in the photoreceptors becoming hyperpolarized and releasing less glutamate, which reduces the inhibition of ON bipolar cells, allowing them to become more active.
This process demonstrates that the visual system relies on a change in retinal activity to encode visual signals for the brain, contrasting with many other sensory systems that primarily rely on an increase in activity to signal a stimulus.