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International Foundation for Optic Nerve Disease

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 ^ M ~Pathway, ~Cell Magnocellular. Referring to large parasol retinal ganglion cells and their axon pathways to the lateral geniculate nucleus layers of the same name.

Wikipedia retinal ganglion cell

 ^ Macula Foveal pit, foveal slope, parafovea, and perifovea together make the macula at the posterior pole of the retina. A yellowish pigment in the cone axons of the Henle Fiber layer in this area is seen on ophthalmoscopy, thus the name Macula Lutea. This pigment acts as an ultraviolet filter for this vital and delicate area of central vision receptors.


 ^ Magnocellular layer Lateral geniculate nucleus layers corresponding to similarly named retinal ganglion cells.

Wikipedia lateral geniculate nucleus

 ^ Marcus Gunn pupil Relative afferent pupillary defect.


 ^ Matrix, Mitochondrial


 ^ MELAS Myopathy, encephalopathy, lactic acidosis, stroke-like episodes. A mitochondrial oxidative phosphorylation genetic disease.


OMIM 540000


 ^ Membrane


 ^ Meninges System of membranes which envelopes the central nervous system including the optic nerve.

Wikipedia Meninges

 ^ Meningioma, of optic nerve sheath

Mitchell V Gossman. Meningioma, Optic Nerve Sheath eMedicine article


 ^ Metabotropic A glutamate neuroreceptor class made of a single polypeptide. It depends on a G-protein and a second messenger cascade to effect separate functions. A subgroup of this receptor class is selectively stimulated by APB. These receptors down regulate cyclic nucleotide synthesis thereby inhibiting separate cGMP gated cation channels, causing a decrease in conductance. One type, mGluR6, is found on the post synaptic membrane of ON-centre bipolar cells. Photo receptors depolarized by the dark cause glutamate release at their presynaptic membranes, stimulating post synaptic mGluR6 of ON center bipolars and inhibiting them from firing. cf Ionotropic


 ^ Microglia


 ^ Microtubule A self assembling structure which is a fundamental part of the cell cytoskeleton (along with intermediate filaments and microfilaments) as well as cell cilia and flagella. Formed from tubulin dimers, they have a plus end where tubulin is added and a minus end where the dimers are removed in a GTP dependant process. They are important in axonal transport of organelles and vesicles. They are conjectured to be the medium of quantum effects involved in hypothetical quantum mechanical mechanisms of consciousness and cancer genesis.

Quantum coherence microtubule PubMed search


 ^ Midget System Parvocellular retinal ganglion cells or P pathway cells projecting in to the parvocellular layers of the lateral geniculate nucleus.


 ^ Mitochondria Bacteria like organelles found in every eukaryotic (animals, plants, and protozoans) cell. The energy engines of cells. They contain the components of the cellular energy producing tricarboxylic acid (Krebs) cycle, the electron transport chain of complexes and oxidative phosphorylation. They are constructed of an outer and inner membrane with an inner matrix. Each one has a circle of DNA (mtDNA) which codes for important functions of the cell. Mutations of mtDNA can cause diseases related to defects in oxidative phosphorylation contributing to many diseases including Leber Hereditary Optic Neuropathy, Parkinson's Disease, Alzheimer's disease and others. See:

Excerpts on Mitochondria and chloroplasts from Molecular Biology of the Cell [NIH Books].

Mitochondria OMIM search mitochondrial genome information

Wikipedia Mitochondria

Wikipedia Mitochondrial DNA

Wikipedia Mitochondrial disease

 ^ Mitochondrial permeability transition pore A protein that is formed in the inner membrane of the mitochondria under certain pathological conditions and has been found to be involved in neurodegeneration. Cyclosporin A is a potent inhibitor of the opening of the mitochondrial permeability transition pore.

Wikipedia Mitochondrial permeability transition pore

Leruez, S., Verny, C., Bonneau, D. et al. Cyclosporine A does not prevent second-eye involvement in Leber’s hereditary optic neuropathy. Orphanet J Rare Dis 13, 33 (2018).

 ^ Mitosis


 ^ MRI, fMRI Magnetic resonance imaging.


 ^ MPTP (1-methyl- 4-phenyl- 1,2,3,6-tetrahydropyridine) Inhibitor of complex I via its metabolite, MPP+. An analogue of meperidine=pethidine. Discovered to induce a Parkinson's disease like disorder.


 ^ MT Visual area V5, also known as visual area MT (middle temporal), is a region of extrastriate visual cortex that is thought to play a major role in the perception of motion.


 ^ Müller Cell see Glia


 ^ Multiple Sclerosis A central nervous system relapsing degenerative disease involving loss of myelin sheath in brain and spinal cord. The optic nerve may become involved in the form of optic neuritis.
See: Intramuscular interferon beta-1a therapy initiated during a first demyelinating event in multiple sclerosis.[registration required for full text] Jacobs LD,* Beck RW, Simon JH, Kinkel RP, Brownscheidle CM, Murray TJ, Simonian NA, Slasor PJ, Sandrock AW, and the CHAMPS Study Group. N Engl J Med 2000;343:898¯904. [PMID 11006365]


 ^ Mutation


 ^ Myelin, ~sheath A membrane coating surrounding nerve axons formed by glial support cells. In the optic nerve the glial cell forming the myelin sheath are are oligodendrocytes as they are in the rest of the central nervous system. In the peripheral nervous system the relevant cells are Schwann cells. It is thought that the difference in regenerative capacity of the peripheral nerves compared to the less regenerative CNS lies in the inhibitory nature of the glial cells.

Mari Dezawa, Emiko Adachi-Usami. Role of Schwann cells in retinal ganglion cell axon regeneration. Progress in Retinal and Eye Research Volume 19, Issue 2 March 2000 Pages 171-204 PMID 9191603

Wong EV, David S, Jacob MH, Jay DG. Inactivation of myelin-associated glycoprotein enhances optic nerve regeneration. J Neurosci. 2003 Apr 15;23(8):3112-7.PMID 12716917


 ^ Myocilin An eye protein implicated with glaucoma by genetic studies and experiments with corticosteroids in eye cells.

Douglas H. Johnson Myocilin and Glaucoma: A TIGR by the Tail? Arch Ophthalmol. 118;974-978, July 2000. PMID 10900113


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