Midget cell
Encyclopedia
A midget cell is one type of retinal ganglion cell. Midget cells originate in the ganglion cell layer
of the retina
, and project to the parvocellular layers of the lateral geniculate nucleus
(LGN). The axons of midget cells travel through the optic nerve
and optic tract
, ultimately synapsing with parvocellular cells in the LGN. These cells are known as midget retinal ganglion cells due to the small sizes of their dendritic trees
and cell bodies. About 80% of RGCs are midget cells. They receive inputs from relatively few rods and cones. In many cases, they are connected to midget bipolar cells, which are linked to one cone each. They have slow conduction velocity, and respond to changes in color but respond only weakly to changes in contrast unless the change is great. They have simple center-surround receptive fields, where the center may be either ON or OFF while the surround is the opposite.
Ganglion cell layer
The ganglion cell layer is a layer of the retina that consists of retinal ganglion cells.In the macula lutea, the layer forms several strata....
of the retina
Retina
The vertebrate retina is a light-sensitive tissue lining the inner surface of the eye. The optics of the eye create an image of the visual world on the retina, which serves much the same function as the film in a camera. Light striking the retina initiates a cascade of chemical and electrical...
, and project to the parvocellular layers of the lateral geniculate nucleus
Lateral geniculate nucleus
The lateral geniculate nucleus is the primary relay center for visual information received from the retina of the eye. The LGN is found inside the thalamus of the brain....
(LGN). The axons of midget cells travel through the optic nerve
Optic nerve
The optic nerve, also called cranial nerve 2, transmits visual information from the retina to the brain. Derived from the embryonic retinal ganglion cell, a diverticulum located in the diencephalon, the optic nerve doesn't regenerate after transection.-Anatomy:The optic nerve is the second of...
and optic tract
Optic tract
The optic tract is a part of the visual system in the brain.It is a continuation of the optic nerve and runs from the optic chiasm to the lateral geniculate nucleus....
, ultimately synapsing with parvocellular cells in the LGN. These cells are known as midget retinal ganglion cells due to the small sizes of their dendritic trees
Dendrite
Dendrites are the branched projections of a neuron that act to conduct the electrochemical stimulation received from other neural cells to the cell body, or soma, of the neuron from which the dendrites project...
and cell bodies. About 80% of RGCs are midget cells. They receive inputs from relatively few rods and cones. In many cases, they are connected to midget bipolar cells, which are linked to one cone each. They have slow conduction velocity, and respond to changes in color but respond only weakly to changes in contrast unless the change is great. They have simple center-surround receptive fields, where the center may be either ON or OFF while the surround is the opposite.