Which cells are most likely responsible for autoregulation within the blood supply of the retina and the optic nerve?

Pericytes are specialized contractile cells located in the walls of small blood vessels, including those in the retina and optic nerve. They play a crucial role in autoregulation, which refers to the ability of blood vessels to maintain stable blood flow despite changes in systemic blood pressure. Specifically, pericytes influence the diameter of capillaries by contracting or relaxing, thereby regulating blood flow and contributing to the overall stability of the retinal microenvironment.

In the context of the retina, the autoregulation of blood supply is essential to meet the metabolic needs of photoreceptors and other retinal cells. When there is an increase in local metabolic demand or a rise in retinal neuronal activity, pericytes respond to these signals by adjusting the capillary blood flow accordingly. This process ensures that the retina receives adequate oxygen and nutrients while efficiently removing waste products.

While other cell types, such as astrocytes, endothelial cells, and microglia, contribute to various functions in the retina, the specific role of pericytes in controlling capillary tone and blood flow dynamics is what makes them particularly important for autoregulation within the blood supply of the retina and the optic nerve.