Question

Can someone explain how the receptive field of photoreceptors (dots of light) build to circles of light for ganglion cells and edges/lines for the visual cortex. I know the ganglion cells build their visual field by combining visual fields of many photoreceptors and that cortical cells build their visual fields by combining the fields of many ganglion cells but what causes this to happen? What is the process? Drawings/Pictures can be helpful too.

Thank you in advance!

Answer 1

Answer :)

Receptive fields of photoreceptors work differently during ON- and OFF conditions. The main cause is the polarization of cells. In the ON-centre bipolar cell, light sparkling on the focal point of a bipolar cell's responsive field and light sparkling on the surrounding produce inverse changes in the cell's layer potential. On the off chance that light is sparkled on the focal point of this present cell's open field, the primary change is a hyperpolarization of the photoreceptor cell, causing depolarization of the bipolar cell, in view of the inhibitory idea of the neural connection between them. This depolarization thusly energizes the accompanying cell, a ganglion cell, making it radiate activity possibilities at a higher recurrence. On the other hand, if light were sparkled on the encompass of the open field of this equivalent ON-focus bipolar cell, it would become hyperpolarized. Conversely, another sort of bipolar cell becomes depolarized when a zone of murkiness strikes the focal point of its open field and hyperpolarized when it strikes the encompass. Bipolar cells of this sort are canceled focus cells. This inside encompasses the structure of the open fields of bipolar cells is transmitted to the ganglion cells through neurotransmitters situated in the inward plexiform layer.