A cellular approach to neurological disease
McKhann, G.M.
Johns Hopkins Medical Journal 143(2): 48-57
1978
ISSN/ISBN: 0021-7263 PMID: 355697 Document Number: 135266
The brain is a highly complex organ, with a marked heterogeneity of cell type. Thus, biochemical studies of whole tissue reflect the composition and metabolism of a mixture of specific cells, subcellular membranes and organelles. Purified populations of specific cell types from brain were isolated to overcome these difficulties. These purified populations can be maintained in vitro and used for studies of cell-specific metabolic processes. Studies of the lipid-synthesizing enzymes are directed toward determining the cellular events taking place during normal and abnormal development. Those of structural proteins are aimed not only at the process of myelination, but also at the process of myelin maintenance. As myelin breaks down, components are released into cerebrospinal fluid. These components can be detected by sensitive assays. A radioimmunoassay for myelin basic protein was developed and used to detect myelin breakdown in patients with multiple sclerosis. Studies to date indicate that patients with multiple sclerosis undergoing active attacks release myelin basic protein into their CSF. In contrast, patients with inactive multiple sclerosis do not have demonstrable quantities of this protein. Thus, knowledge of the specific composition of myelin has led to the development of a biochemical test of the activity of demyelinative disease.