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Myelinogenesis is the formation and development of myelin sheaths in the nervous system, typically initiated in late prenatal neurodevelopment and continuing throughout postnatal development. [1] Myelinogenesis continues throughout the lifespan to support learning and memory via neural circuit plasticity as well as remyelination following ...
Oligodendrocytes are a type of glial cell, non-neuronal cells in the central nervous system.They arise during development from oligodendrocyte precursor cells (OPCs), [8] which can be identified by their expression of a number of antigens, including the ganglioside GD3, [9] [10] [11] the NG2 chondroitin sulfate proteoglycan, and the platelet-derived growth factor-alpha receptor subunit (PDGF ...
In neuroscience, the axolemma (from Greek lemma 'membrane, envelope', and 'axo-' from axon [1]) is the cell membrane of an axon, [1] the branch of a neuron through which signals (action potentials) are transmitted. The axolemma is a three-layered, bilipid membrane. Under standard electron microscope preparations, the structure is approximately ...
Activity-independent mechanisms are generally believed to occur as hardwired processes determined by genetic programs that are played out within individual neurons. These include differentiation, migration, and axon guidance to their initial target areas. These processes are thought of as being independent of neural activity and sensory experience.
Embryonically derived stem cells have been demonstrated to carry out remyelination under laboratory conditions, but some religious groups are opposed to their use. [ citation needed ] Adult central nervous system stem cells have also been shown to generate myelinating oligodendrocytes, but are not readily accessible.
Myelin (/ ˈ m aɪ. ə l ɪ n / MY-ə-lin) is a lipid-rich material that surrounds nerve cell axons to insulate them and increase the rate at which electrical impulses (called action potentials) pass along the axon. [1] [2] The myelinated axon can be likened to an electrical wire (the axon) with insulating material (myelin) around it. However ...
The action potential travels from one location in the cell to another, but ion flow across the membrane occurs only at the nodes of Ranvier. As a result, the action potential signal jumps along the axon, from node to node, rather than propagating smoothly, as they do in axons that lack a myelin sheath.
The transition between the CNS and PNS occurs at the level of the pia mater, the innermost and most delicate layer of meningeal tissue surrounding components of the CNS. The axon of an α-MN connects with its extrafusal muscle fiber via a neuromuscular junction , a specialized type of chemical synapse that differs both in structure and function ...