Midget cell

Midget cells are a type of retinal ganglion cell that are found in the primate retina. They are named for their relatively small size compared to other retinal ganglion cells. Midget cells are involved in the perception of color and fine detail, and they constitute the majority of ganglion cells in the central retina, an area responsible for high-acuity vision.

Anatomy and Function

Midget cells receive input from bipolar cells, which in turn receive input from a single cone photoreceptor. This one-to-one connection is unique to midget cells and is responsible for their role in high-resolution vision.

Midget cells are divided into two types: parvocellular (P cells) and magnocellular (M cells). P cells are smaller and slower, but they are more numerous and have a higher spatial resolution. M cells are larger and faster, but they have a lower spatial resolution.

Role in Vision

Midget cells play a crucial role in color perception. They receive input from L and M cones, the two types of cones that are sensitive to long-wavelength and medium-wavelength light, respectively. The difference in signals from these two types of cones allows the brain to perceive color.

Midget cells also contribute to the perception of fine detail. Because each midget cell receives input from a single cone, it can relay information about a very specific point in the visual field. This allows for high-acuity vision, particularly in the central retina.

Clinical Significance

Damage to midget cells can result in a variety of visual impairments. For example, glaucoma often affects midget cells, leading to loss of color vision and fine detail perception. Research into midget cells may therefore be important for developing treatments for this and other eye diseases.