Parvocellular

Parvocellular refers to one of the two types of cells in the visual system's lateral geniculate nucleus (LGN) of the thalamus. The term "parvocellular" is derived from Latin, where "parvo" means small, and "cellular" refers to cells. This is in reference to the relatively small size of parvocellular cells compared to magnocellular cells, the other type of cells in the LGN.

Function

Parvocellular cells are responsible for encoding color, fine detail, and slow-moving or stationary objects in the visual field. They have a high color spatial resolution, allowing them to distinguish between different colors and detect fine details. However, they have a low temporal resolution, meaning they are less effective at detecting motion.

Structure

Parvocellular cells are smaller than magnocellular cells, hence their name. They receive input primarily from midget cells in the retina, which are also small and have a high spatial resolution. Parvocellular cells are located in the parvocellular layers of the LGN, which are the top four layers.

Parvocellular Pathway

The parvocellular pathway, also known as the P pathway, is the pathway in the visual system that involves parvocellular cells. It begins in the retina, where light is detected by cone cells. The information is then transmitted to midget cells, which send the information to parvocellular cells in the LGN. From there, the information is sent to the primary visual cortex (V1) in the occipital lobe of the brain.

Clinical Significance

Damage to the parvocellular pathway can result in a variety of visual impairments, including difficulties with color perception and fine detail. It can also result in achromatopsia, a condition characterized by a severe deficiency in color discrimination.

See Also

• Magnocellular cells
• Visual system
• Lateral geniculate nucleus
• Thalamus
• Retina
• Midget cells
• Cone cells
• Primary visual cortex
• Occipital lobe
• Achromatopsia