What is the role of horizontal cells bipolar cells and interneurons in the retina?
Horizontal cells (HCs) and amacrine cells (ACs), two types of retinal interneurons, modulate the information flow from photoreceptors (PRs) to bipolar cells (BCs) in the outer plexiform layer (OPL) and from BCs to retinal ganglion cells (RGCs) in the inner plexiform layer (IPL), respectively.
What is the role 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.
What are retinal bipolar cells?
Bipolar cells are the only neurons that connect the outer retina to the inner retina. They implement an ‘extra’ layer of processing that is not typically found in other sensory organs.
What is the function of the horizontal bipolar and amacrine cells of the eye?
Horizontal Cells and amacrine cells perform intermediate and lateral processing by integrating information at the bipolar and ganglion cell layers, respectively.
What is the purpose of horizontal cells in the eye?
Horizontal cells are the laterally interconnecting neurons in the Inner Nuclear (Bipolar) layer of the retina ofmammalian eyes. They help integrate and regulate the input from multiple photoreceptor cells.
What is the role of horizontal cells?
Horizontal cells receive excitatory input from photoreceptors and provide feedback inhibition to photoreceptors and feedforward inhibition to bipolar cells.
What are horizontal cells of retina?
Horizontal cells are the laterally interconnecting neurons having cell bodies in the inner nuclear layer of the retina of vertebrate eyes. They help integrate and regulate the input from multiple photoreceptor cells.
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.
How many bipolar cells are in retina?
There are roughly 10 distinct forms of cone bipolar cells, however, only one rod bipolar cell, due to the rod receptor arriving later in the evolutionary history than the cone receptor.
What are horizontal cells and bipolar cells?
Bipolar cells effectively transfer information from rods and cones to ganglion cells. The horizontal cells and the amacrine cells complicate matters somewhat. The horizontal cells introduce lateral inhibition to the dendrites and give rise to the center-surround inhibition which is apparent in retinal receptive fields.
What are horizontal cells in retina?
Do horizontal cells synapse with bipolar cells?
Horizontal cells span across photoreceptors and summate inputs before synapsing onto photoreceptor cells. Horizontal cells may also synapse onto bipolar cells, but this remains uncertain. There is a greater density of horizontal cells towards the central region of the retina.
What does retinal bipolar cells mean?
Within the retina, bipolar cells act as the signal couriers between the photoreceptors that react to light stimuli and the ganglion cells that carry these signals out of the eye and into the cortex. Bipolar cells are so-called because they have two polar extensions that protrude from opposite ends of the soma (cell body).
What is the function of bipolar cells?
Bipolar cells are specialized sensory neurons for the transmission of special senses. As such, they are part of the sensory pathways for smell, sight, taste, hearing and vestibular functions.
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 off-center bipolar cell?
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). Bipolar cells with ON-OFF responses were not encountered (1).