A Look at Myelin and Myelin-Related Disorders Essay -- Biology Essays

A Look at Myelin and Myelin-Related Disorders Myelin is the protective sheath around axons in the nervous system, and is often referred to as 'white matter.' It acts as an insulator to the electrical signal that is conducted down the axon as a neuron fires, and can well be compared to the insulation around an electrical wire. The myelin sheath contains a variety of fatty substances (lipids), and contains at least ten distinct chemicals (2). . From what is known, axons are not fully myelinated at birth, but myelin is formed from birth on into the second decade of life (3). The way myelination takes place is through glial cells wrapping around the axons in a spiral fashion. The axons are originally embedded in these glial cells, and the cell's membranes extend to wrap the axon tightly and repeatedly. 'Glia' comes from Greek, meaning 'glue,' hinting at the way the cell's membrane sticks to the axon, and how the different layers of the extended membrane stick to each other. There are different glial cells that form myelin: in the ce ntral nervous system, these cells are referred to as oligodendrocytes, and in the peripheral nervous system they are Schwann cells. While in the peripheral nervous system the glial cell wraps around a single axon to insulate it, in the central nervous system a glial cell may wrap around several axons at once (4).. The characteristics and specific functions of myelin have not fully been explored by researchers, and as far as I can tell most current research efforts are initiated by groups that research myelin-related disorders, such as the Myelin Profect. In demyelinating diseases, the myelin sheath around some axons is targeted. These diseases fall into two main groups: acquired diseases and heredit... ...bout the leukodystrophies http://www.ulf.org/ulf/intro/#inf1 3) Myelin Disorders Menu