Biomaterial Database

Ultrastructural sequence of myelin degradation. II. Wallerian degeneration in the rat femoral nerve. 1978

H Lassmann, and H P Ammerer, and W Jurecka, and W Kulnig

Myelin degradation in Wallerian degeneration of rat femoral nerves has been studied with the electron microscope. In the initial stages, a decrease of myelin periodicity from 115 A to 88 A was noted, followed by the transformation of the myelin structure into uniformly layered lipid inclusions. 10--14 days after nerve section, most of the inclusions found represented unstructured lipid droplets or crystals. In the later stages of degeneration, numerous pleomorphic lamellar inclusions were found, some of them resembling the structure of pi and micron-granules. Lysosomal enzyme activity was found especially in pleomorphic inclusions during the late stages of myelin degradation. Normal myelin sheaths, as well as unstructured lipid droplets and crystals, were devoid of enzyme activity. The results are compared with alterations found in Wallerian degeneration of the central nervous system.

UI	MeSH Term	Description	Entries
D008247	Lysosomes	A class of morphologically heterogeneous cytoplasmic particles in animal and plant tissues characterized by their content of hydrolytic enzymes and the structure-linked latency of these enzymes. The intracellular functions of lysosomes depend on their lytic potential. The single unit membrane of the lysosome acts as a barrier between the enzymes enclosed in the lysosome and the external substrate. The activity of the enzymes contained in lysosomes is limited or nil unless the vesicle in which they are enclosed is ruptured or undergoes MEMBRANE FUSION. (From Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed).	Autolysosome,Autolysosomes,Lysosome
D008854	Microscopy, Electron	Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.	Electron Microscopy
D009185	Myelin Proteins	MYELIN-specific proteins that play a structural or regulatory role in the genesis and maintenance of the lamellar MYELIN SHEATH structure.	Myelin Protein,Protein, Myelin,Proteins, Myelin
D009186	Myelin Sheath	The lipid-rich sheath surrounding AXONS in both the CENTRAL NERVOUS SYSTEMS and PERIPHERAL NERVOUS SYSTEM. The myelin sheath is an electrical insulator and allows faster and more energetically efficient conduction of impulses. The sheath is formed by the cell membranes of glial cells (SCHWANN CELLS in the peripheral and OLIGODENDROGLIA in the central nervous system). Deterioration of the sheath in DEMYELINATING DISEASES is a serious clinical problem.	Myelin,Myelin Sheaths,Sheath, Myelin,Sheaths, Myelin
D009410	Nerve Degeneration	Loss of functional activity and trophic degeneration of nerve axons and their terminal arborizations following the destruction of their cells of origin or interruption of their continuity with these cells. The pathology is characteristic of neurodegenerative diseases. Often the process of nerve degeneration is studied in research on neuroanatomical localization and correlation of the neurophysiology of neural pathways.	Neuron Degeneration,Degeneration, Nerve,Degeneration, Neuron,Degenerations, Nerve,Degenerations, Neuron,Nerve Degenerations,Neuron Degenerations
D002479	Inclusion Bodies	A generic term for any circumscribed mass of foreign (e.g., lead or viruses) or metabolically inactive materials (e.g., ceroid or MALLORY BODIES), within the cytoplasm or nucleus of a cell. Inclusion bodies are in cells infected with certain filtrable viruses, observed especially in nerve, epithelial, or endothelial cells. (Stedman, 25th ed)	Cellular Inclusions,Cytoplasmic Inclusions,Bodies, Inclusion,Body, Inclusion,Cellular Inclusion,Cytoplasmic Inclusion,Inclusion Body,Inclusion, Cellular,Inclusion, Cytoplasmic,Inclusions, Cellular,Inclusions, Cytoplasmic
D005267	Femoral Nerve	A nerve originating in the lumbar spinal cord (usually L2 to L4) and traveling through the lumbar plexus to provide motor innervation to extensors of the thigh and sensory innervation to parts of the thigh, lower leg, and foot, and to the hip and knee joints.	Femoral Nerves,Nerve, Femoral,Nerves, Femoral
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013997	Time Factors	Elements of limited time intervals, contributing to particular results or situations.	Time Series,Factor, Time,Time Factor
D014855	Wallerian Degeneration	Degeneration of distal aspects of a nerve axon following injury to the cell body or proximal portion of the axon. The process is characterized by fragmentation of the axon and its MYELIN SHEATH.	Degeneration, Wallerian