LIFESCI 3B03 Lecture 10: Module 3 lecture note
7 Feb 2017
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Glial myelinating cells: schwan cells in the pns . Can myelinate axons one at a time the whole cell involved in axon myelination. In non-myelinated axons are protected or encapsulated by schwan cell\9protection of unmyelinated axons: oligodendrocytes in the pns. Think about the importance of losing one oligodendrocyte versus one. Higher cost as one oligo can myelinate 40 axons. Myelin characteristic: modified portion of the membrane of cells, predominant element of white matter. White matter contains axons, glial cells, blood vessels: composition, most biological membrane have higher protein: lipid ratio, 70-85% dry weight lipid and 15-30% protein. Membrane model: lipid bilayer w/ integral proteins, extrinsic proteins attached to one surface or another by weak linkages, proteins and lipids asymmetrically distributed in bilayer. Major dense line- as you wrap membrane you also enclose extracellular fluid- it is cytoplasm vs intraperiod line in extracellular fluid.
