The myelin sheath plays an important role as the axon in the functioning of the neural system, and myelin degradation is a hallmark pathology of multiple sclerosis and spinal cord injury. Electron microscopy, fluorescent microscopy, and magnetic resonance imaging are three major techniques used for myelin visualization. However, microscopic observation of myelin in living organisms remains a ch...

A sensitive radioimmunoassay that can detect brain damage in cases of head injury and stroke was applied to blood samples from 13 patients before and after they received multiple treatments with electroconvulsive therapy for psychiatric disorder. None of the patients showed a significant increase in serum myelin basic protein immunoreactivity. As increased serum myelin basic protein immunoreact...

High-affinity muscarinic cholinergic receptors were detected in myelin purified from rat brain stem with use of the radioligands 3H-N-methylscopolamine (3H-NMS), 3H-quinuclidinyl benzilate (3H-QNB), and 3H-pirenzepine. 3H-NMS binding was also present in myelin isolated from corpus callosum. In contrast, several other receptor types, including alpha 1- and alpha 2-adrenergic receptors, present i...

Specific antibodies have been developed against P1, P2, and P0 myelin proteins and were used to study the localization of these proteins in the rat peripheral nervous system. Both peripheral and central nervous system myelin sheaths contain P1 protein. P0 and P2 proteins are found exclusively in peripheral nervous system myelin sheaths. Antisera to P1 and P0 proteins stain all peripheral nervou...

It has been hypothesized that myelin acts like a mitochondrion, generating ATP across the membranes of its sheath. By calculating the proton motive force across the myelin membrane based on known values for the pH and membrane potential of the oligodendrocyte, we find that insufficient energy could be harvested from proton flow across the myelin membrane to synthesize ATP. In fact, if the respi...

Until the advent of MR imaging, knowledge of the structure of myelin and the process of myelination were of little importance to the neuroradiologist. Other than some mild changes in the attenuation of white matter, myelination resulted in no significant alterations of CT (1) or sonographic studies. MR studies, on the other hand, have been increasingly used for pediatric brain imaging. MR imagi...

Schwann cells in the peripheral nervous systems extend their membranes to wrap axons concentrically and form the insulating sheath, called myelin. The spaces between layers of myelin are sealed by myelin junctions. This tight insulation enables rapid conduction of electric impulses (action potentials) through axons. Demyelination (stripping off the insulating sheath) has been widely regarded as...

The effect of aging on myelin sheaths in the rhesus monkey was studied in the vertical bundles of nerve fibers that traverse monkey cerebral cortex in primary visual area 17 and prefrontal area 46. As shown previously, with age the internodes of many of these myelin sheaths show structural changes, the most common of which is an accumulation of electron-dense cytoplasm within some sheaths, a ch...

A time-sequence study of the incorporation and distribution of cholesterol in peripheral nerve myelin was carried out by electron microscope autoradiography. [1,2-(3)H]Cholesterol was injected into 10-day old mice and the sciatic nerves were dissected out at 10, 20, 40, 60, 90, 120, and 180 min after the injection. 20 min after injection the higher densities of grains due to the presence of [(3...

Peculiar myelin figures were abundantly found in some basal-granulated cells including S, D1 and I cells in human Brunner's glands. Intense acid phosphatase activity was found in the periphery of the myelin figures, indicating that they were secondary lysosomes or residual bodies. The acid phosphatase activity was also found in some secretory granules. There were some secretory granules which w...