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Inflammatory demyelinating diseases (IDDs), sometimes called Idiopathic (IIDDs) due to the unknown etiology of some of them, are a heterogenous group of demyelinating diseases - conditions that cause damage to myelin, the protective sheath of nerve fibers - that occur against the background of an acute or chronic inflammatory process.
Myelin is formed by oligodendrocytes in the central nervous system and Schwann cells in the peripheral nervous system.Therefore, the first stage of myelinogenesis is often defined as the differentiation of oligodendrocyte progenitor cells (OPCs) or Schwann cell progenitors into their mature counterparts, [4] followed by myelin formation around axons.
This is probably linked with down regulation of certain expressed genes with increased age. The research of this is particularly important with the elderly whose myelin and axons are more prone to be degenerated in the CNS. [1] [15] [16] Class 3 semaphorins (SEMA3s), originally identified as axon guidance molecules, play a role in remyelination.
Neuroregeneration is the regrowth or repair of nervous tissues, cells or cell products. Neuroregenerative mechanisms may include generation of new neurons, glia, axons, myelin, or synapses.
The process of generating myelin is called myelination or myelinogenesis. In the CNS, oligodendrocyte progenitor cells (OPCs) differentiate into mature oligodendrocytes, which form myelin. In humans, myelination begins early in the 3rd trimester, [ 11 ] although only little myelin is present in either the CNS or the PNS at the time of birth.
Myelin sheath of a healthy neuron in the central nervous system. Multiple sclerosis is an inflammatory demyelinating disease of the CNS in which activated immune cells invade the central nervous system and cause inflammation, neurodegeneration, and tissue damage.
[27] [4] It affects about 6% of people 65 years and older, [16] and women more often than men. [28] The disease is named after German psychiatrist and pathologist Alois Alzheimer, who first described it in 1906. [29] Alzheimer's financial burden on society is large, with an estimated global annual cost of US$1 trillion. [14]
White matter is the tissue through which messages pass between different areas of grey matter within the central nervous system. The white matter is white because of the fatty substance (myelin) that surrounds the nerve fibers (axons). This myelin is found in almost all long nerve fibers, and acts as an electrical insulation.