Lateral geniculate nucleus:

nucleus in the thalamus that receives visual information from the retina and sends it to the visual cortex for processing. The lateral geniculate nucleus exhibits a layered structure. There are two magnocellular layers, four parvocellular layers, and koniocellular layers between each of the magnocellular and parvocellular layers.

 

Magnocellular cells: 

AKA M-cells. Magnocellular cells make up the magnocellular layers of the lateral geniculate nucleus. They are relatively large cells that display specialization in detecting aspects of movement, such as the location, speed, and direction of a moving object.

 

Parvocellular cells:

AKA P-cells. Parvocellular cells make up the parvocellular layers of the lateral geniculate nucleus. They are relatively small compared to magnocellular cells and are important for spatial resolution, visual acuity, and the detailed analysis of shape, size, and color. 

 

Koniocellular cells:

AKA K-cells. Koniocellular cells make up the koniocellular layers of the lateral geniculate nucleus. They are small cells whose function is still not fully understood. They are thought to be involved with some aspects of color vision, and seem to specifically be involved with processing information from short-wavelength sensitive cone cells in the retina.