What is the function of bipolar cells in the retina?
Bipolar cells are one of the main retinal interneurons and provide the main pathways from photoreceptors to ganglion cells, i.e. the shortest and most direct pathways between the input and output of visual signals in the retina.
Which cells form the bipolar layer of the retina?
Retina bipolar cell
| Retinal bipolar cell | |
|---|---|
| Location | Retina (inner nuclear layer) |
| Shape | bipolar |
| Function | Convey gradients between photoreceptor cells to retinal ganglion cells |
| Neurotransmitter | Glutamate |
Are bipolar neurons in the retina?
Bipolar cells (BCs) are the central neurons of the retina which carry light-elicited signals from photoreceptors and horizontal cells (HCs) in the outer retina to amacrine cells (ACs) and ganglion cells (GCs) in the inner retina.
Where are bipolar cells found?
Often found in the retina, bipolar cells are crucial as they serve as both direct and indirect cell pathways. The specific location of the bipolar cells allow them to facilitate the passage of signals from where they start in the receptors to where they arrive at the amacrine and ganglion cells.
How many bipolar cells are in the retina?
There are more than ten types of bipolar cells in the mammalian retina. These typically consist of slightly more ON than OFF types (for examples, see Refs 12,13) plus a single type of rod bipolar cell (Box 1; Fig. 1b). However, this pattern may vary substantially in non-mammalian vertebrates.
What do bipolar cells release?
Light responses in bipolar cells are initiated by synapses with photoreceptors. Photoreceptors release only one neurotransmitter, glutamate (21); yet bipolar cells react to this stimulus with two different responses, ON-center (glutamate hyperpolarization) and OFF-center (glutamate depolarization).
Why are they called bipolar cells?
They act, directly or indirectly, to transmit signals from the photoreceptors to the ganglion cells. Bipolar cells are so-named as they have a central body from which two sets of processes arise. They can synapse with either rods or cones (but not both), and they also accept synapses from horizontal cells.
Are bipolar cells hyperpolarized?
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 bipolar neurons commonly found?
Bipolar neurons are found in the retina of the eye, roof of the nasal cavity, and inner ear. They are always sensory and carry information about vision, olfaction, equilibrium, and hearing.
What happens to bipolar cells when light hits the retina?
The visual pathway in the retina consists of a chain of different nerve cells. Light first travels through all the layers until it reaches the photoreceptor layer, the rod and cone layer. Bipolar cells can either hyperpolarize or depolarize with light, and they pass their signal on to amacrine cells or ganglion cells.
Where are bipolar cells located in the eye?
inner nuclear layer
The synapses between photoreceptor terminals and bipolar cells (and horizontal cells) occur in the outer plexiform layer; more specifically, the cell bodies of photoreceptors make up the outer nuclear layer, whereas the cell bodies of bipolar cells lie in the inner nuclear layer.
How many bipolar cells are there?
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.
What is on-center bipolar cell?
On-center bipolar cells have inhibitory synapses with the photoreceptors and therefore are excited by light and suppressed in the dark. Bipolar neurons exist within the vestibular nerve as it is responsible for special sensory sensations including hearing, equilibrium and motion detection.
What is bipolar cell layer?
Bipolar Cells. The definition of bipolar cells refers to making dual connections forward and outward to the ganglion cells, as well as backward and inward to the third layer of retinal cells.
What is the structure of a bipolar neuron?
A neuron that is bipolar is one that has two extensions protruding in opposite directions, giving it the appearance of having arms. Alternatives include multipolar neurons, which have many protrusions, or pseudonuipolar neurons, which have two sets of both an axon and a dendrite running in opposite directions.
What is a retinal ganglion cell?
Retinal Ganglion Cell. Definition. Retinal ganglion cells (RGCs) relay visual information from their cell soma located in the retina, through their axons which project along the optic nerve to the brain.