Sam Schmidt Paralysis Foundation a cell body, which houses the nucleus. Axons and dendrites form extensions from the cell body. Glial cells are "nerve-helper" cells that provide structural support, nourishment and protection for neurons. Astrocytes, a kind of glial cell, are the primary support cells of the brain and spinal cord. They make and secrete proteins called neurotrophic factors, which assist in the maintenance of nerve cells in the central nervous system. They also break down and remove proteins or chemicals that might be harmful to neurons (for example, glutamate, a neurotransmitter that in excess causes cells to become overexcited and die by a
Satellite glial cell in the same sheath (reflexive gap junctions). These gap junctions have been identified through the use of electron microscopy and weight tracer markers, such as Lucifer yellow or neurobiotin. The degree to which SGCs are coupled to SGCs of another sheath or to SGCs of the same sheath is dependent on the pH of the cellular environment. From studies on rats and mice, researchers have found that satellite glial cells express many neurotransmitter receptors, such as muscarinic acetylcholine and erythropoietin receptors. In order to differentiate between SGCs and other glial cells researchers have used markers to identify which proteins are