Astrocytes are the neuroglial cells of the central nervous system. They are the supporting structures for the main cell of the tissue, the neurons. It derived its name from its star-shaped appearance. The big cell body with its branching processes provides the characteristic appearance of the cell. When viewed under the microscope, you can easily distinguish them by their shape. Physiologically, the astrocytes play different roles in the body. Here are some of the notable significances of the cells.
Blood Brain Barrier
Astrocytes form part of the blood brain barrier. The long processes combine with the endothelial cells to make a distinction from the circulating blood and the cerebrospinal fluid found in the brain. The barricade stops the entry of large molecular substances and allows only the smaller molecules to pass through it. This way, bacteria and other harmful substances will not infect the brain. However, the same barrier can make treatment targeting the brain more difficult. Because drugs are macromolecules, very few can pass the obstacle. Therefore, medicines targeting the brain must bypass the barrier for it to become effective.
As a type of glial cells, the astrocytes provide nourishment for the neurons in the nervous system. They produce lactate to be used in their metabolism. By providing the needed nutrients, neurons can perform its function in delivering electrical impulses.
Astrocytes also take part in the repair of damaged tissues. When an injury occurs in the brain, the cells perform a phagocytic function by ingesting the worn-out nerve cell. After clearing the debris, they create the glial scar that will replace the non-regenerative neurons.
As more research is ongoing regarding the brain functions, scientists find more of the possible functions of the astrocytes. In recent findings, they hypothesize that the cell can also play a role in stimulating the regeneration of the neurons. However, everything is yet to be discovered.