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Schwann cells (TA: Gliocytus periphericus) (named after physiologist Theodor Schwann) or neurolemmocytes are the principal glia of the peripheral nervous system (PNS). Glial cells function to support neurons and in the PNS, also include satellite cells, olfactory ensheathing cells, enteric glia and glia that reside at sensory nerve endings, such as the Pacinian corpuscle. There are two types of Schwann cell, myelinating and nonmyelinating. Myelinating Schwann cells wrap around axons of motor and sensory neurons to form the myelin sheath. The Schwann cell promoter is present in the Downstream region of the Human Dystrophin Gene that gives shortened transcript that are again synthesized in a tissue specific manner. Schwann cells are involved in many important aspects of peripheral nerve biology—the conduction of nervous impulses along axons, nerve development and regeneration, trophic support for neurons, production of the nerve extracellular matrix, modulation of neuromuscular synaptic activity, and presentation of antigens to T-lymphocytes. Charcot–Marie–Tooth disease (CMT), Guillain–Barré syndrome (GBS, acute inflammatory demyelinating polyradiculopathy type), schwannomatosis, and chronic inflammatory demyelinating polyneuropathy (CIDP), and leprosy are all neuropathies involving Schwann cells. ==Structure== Schwann cells are a variety of glial cell that keep peripheral nerve fibres (both myelinated and unmyelinated) alive. In myelinated axons, Schwann cells form the myelin sheath (see above). The sheath is not continuous. Individual myelinating Schwann cells cover about 100 micrometres of an axon—equating to approximately 10,000 Schwann cells along a 1 metre length of the axon. The gaps between adjacent Schwann cells are called nodes of Ranvier (see above). 9-O-acetyl GD3 ganglioside is an acetylated glycolipid which is found in the cell membranes of many types of vertebrate cells. During peripheral nerve regeneration, 9-O-acetyl GD3 is expressed by Schwann cells. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Schwann cell」の詳細全文を読む スポンサード リンク
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