What are on and off cells?
ON-center cells are depolarized by illumination of their receptive field center (RFC), while OFF-center cells are depolarized by decreased illumination of their RFC. Along with the vertical excitatory pathways from cones to bipolar cells to ganglion cells, there are two stages of lateral inhibition.
What is the difference between ON and OFF bipolar cells?
ON-center bipolar cells are depolarized by small spot stimuli positioned in the receptive field center. OFF-center bipolar cells are hyperpolarized by the same stimuli. Both types are repolarized by light stimulation of the peripheral receptive field outside the center (Fig. 1).
What are on center off surround cells?
ON center/OFF surround cell: Flashing small bright spot in the center subregion increases the cell’s response. An OFF-center/ON-surround ganglion cell has the opposite arrangement. It gets inhibition from a small spot of light in the center, and excitation from an annulus in the surround.
What is an on center cell?
a retinal ganglion cell that is excited by light in the center of its receptive field but is inhibited by light in the surround.
What is an off bipolar cell?
Because glutamate release is decreased upon exposure to light, a bipolar cell that responds to glutamate by excitation will be excited when the light is off. These are called off-center bipolar cells because they are active when the light is off in the center of their receptive field (Figure 4.8. 8).
What are the on and off RGCs in the retina?
Subpopulations of alpha/Y RGCs have dendrites that stratify in either the proximal or distal inner plexiform layer of the retina corresponding to their ON-center and OFF-center receptive fields (ON RGCs increase firing in response to light increments whereas OFF RGCs increase firing in response to light decrements).
What is the purpose of ON and OFF bipolar cells?
There are two types of bipolar cells, both of which receive the glutamate neurotransmitter, but the ON-center bipolar cells will depolarize, whereas the OFF-center bipolar cells will hyperpolarize. This arrangement helps provide a spatial processing of the visual input derived from the photoreceptor cells.
HOW DO ON and OFF bipolar cells work?
What are off cells?
off cells (OFF cells) neurons in the visual system, particularly the retina, that depolarize when the retina is stimulated by light offset.
What is the purpose of on center and off center ganglion cells?
On center and off center retinal ganglion cells respond oppositely to light in the center and surround of their receptive fields. A strong response means high frequency firing, a weak response is firing at a low frequency, and no response means no action potential is fired.
Why do we need ON and OFF bipolar cells?