Alphabetical list

Macroconnection ( Thompson & Swanson, 2010 ) : A connection between two gray matter regions; p. 15239. At this level of analysis gray matter regions are treated as black box nodes, disregarding their composition of neuron types (Bota & Swanson, 2007) and local connections. That is, macroconnections are described to and from particular gray matter regions, disregarding local connections within the gray matter regions. In normal, healthy animals global macroconnection patterns are genetically hardwired. more details

Macropathway : A pathway between two gray matter regions. more details

Marginal ganglion : A topographic division with a small condensation of neurons (Waldeyer, 1891), outside of a nerve ring, in a nerve net of at least some active Coelenterate medusae, Ctenophora, and Echinoderms; see Bullock & Horridge (1965, Ch. 8), Cobb (1995). more details

Medial ( Schulze, 1893 ) : Toward the median plane (Henle, 1855) of the body, in the frontal plane (Henle, 1855); the opposite of lateral (Barclay, 1803); used thus by Schulze (1893, p. 6). Also see Brusca & Brusca (1990, p. 46). more details

Median plane ( Henle, 1855 ) : The sagittal plane (Henle, 1855) dividing a body into roughly equal right and left halves; term introduced by Henle (1855, p. 1); also see Standring (2008, Fig. 1). Synonyms include midline and midsagittal plane. more details

Mediolateral axis : In animals with bilateral symmetry an axis orthogonal to the rostrocaudal axis that lies in the frontal plane (Henle, 1855). It is unusual in having a right and left half reflected across the median plane (Henle, 1855); that is, for the right and left sides of the body, medial (Schulze, 1893) is toward the median plane and lateral (Barclay, 1803) is toward the right or left edge of the body. A synonym is right-left axis; see Kuhlenbeck (1973, p. 112). more details

Medulla ( MY ; Winslow, 1733 ) : The topographic division of the cerebrospinal axis (Meckel, 1817) between pons (Haller, 1747) and spinal cord (Galen, c162-c166). It was clearly described and illustrated for macrodissected adult humans by Piccolomini (1586, pp. 265, 269; his intracranial medulla oblongata), while the term medulla was used by Winslow (1733, Sect. X, p. 42) and Haller (1747, see translation by Mihles, 1754, pp. 287, 286), and more recently in the classic textbooks of for example Mettler (1948, p. 76) and Carpenter (1976, p. 60). Synonyms include medulla oblongata (Bartholin, 1651), spinal bulb (Chaussier, 1807), bulb (Chaussier, 1807), afterbrain (Baer, 1837), metencephalon (Sharpey et al., 1867), myelencephalon (Huxley, 1871), epencephalon (Mihailkovics, 1877). more details

Medulla oblongata ( Bartholin, 1651 ) : Synonym for medulla (Winslow, 1733); probably introduced by Bartholin (1651, p. 317) and clearly used thus by Collins (1685, Tab. 48-M). more details

Medulla spinalis ( Hippocrates ) : Latin form of spinal cord (Galen, c162-c166), introduced (in Greek) by Hippocrates in On the Sacred Disease and Fleshes, see translations by Adams (1972, pp. 234, 309) and Potter (1995, p. 139), respectively, and May (1968, p. 575). more details

Meninges ( MEN ; Edwin Smith Surgical Papyrus, c1700 BC ) : The connective tissue coverings of the nervous system (Monro, 1783) that in mammals are divided concentrically from outside to inside into dura (Galen, c177), arachnoid (Blasius, 1666), and pia (Galen, c192), which often extends along blood vessels into the central nervous system (Meckel, 1817). A term equivalent to the Greek "meninx"-membrane, in the present context a fibrous membrane around the brain (Edwin Smith Surgical Papyrus, c1700 BC)-was used to describe a human head wound in the Edwin Smith Surgical Papyrus, a c1700 BC copy of a manuscript composed c3200 BC; see Breasted (1930, pp. 65, 167, 171-172), Clarke & O'Malley (1996, p. 384), Allen (2005, p. 75). more details

Mesencephalon ( Sharpey et al., 1867 ) : Latin form of midbrain (Baer, 1837); it was introduced for macrodissected adult humans by Sharpey et al. (1867, p. 577), who also introduced the English, "midbrain". more details

Mesoconnection ( Thompson & Swanson, 2010 ) : A connection between two neuron types (Bota & Swanson, 2007), or between a neuron type (Bota & Swanson, 2007) and another cell type like muscle or gland cells; p. 15239. At this level of analysis all axon connections from (outputs of) a particular neuron type (Bota & Swanson, 2007) are arranged in terms of a stereotyped collateralization (branching) pattern of the axon trunks of the neuron type (Bota & Swanson, 2007), with individual axon collaterals innervating specific neuron types (Bota & Swanson, 2007)-the individual axon connections of the neuron type. At this level of analysis mesoconnections are established by synapses (Foster & Sherrington, 1897). In normal, healthy animals global mesoconnection patterns are genetically hardwired. more details

Mesopathway : A pathway between two neuron types (Bota & Swanson, 2007). more details

Metencephalon ( Huxley, 1871 ) : Synonym for epencephalon (Sharpey et al., 1867) and thus hindbrain (Baer, 1837); p. 60. Wilder (1899, p. 573) regarded the shifting of afterbrain (Baer, 1837) and thus metencephalon (Sharpey et al., 1867) from the last position to the penultimate position, and replacing metencephalon (Sharpey et al., 1867) with myelencephalon (Huxley, 1871)-which had previously referred to the cerebrospinal axis (Meckel, 1817) as a whole: myelencephalon (Owen, 1868)-as "constituting a violation of scientific ethics that merits the severest reprobation"! The situation is perfectly illustrated by comparing Gehuchten (1893, Figs. 32, 33) with Gehuchen (1906, Fig. 14)-before and after His (1895, Fig. 20 and p. 162). more details

Metencephalon ( Sharpey et al., 1867 ) : Original Latin form of afterbrain (Baer, 1837), that is, the medulla (Winslow, 1733); see p. 577. Also see metencephalon (Huxley, 1871). more details

Metencephalon ( Williams & Warwick, 1980 ) : Synonym for macrodissected adult human pons (Haller, 1747); p. 864. more details

Microconnection ( Thompson & Swanson, 2010 ) : A connection between two individual neurons (Waldeyer, 1891), or between one neuron and another cell like a muscle or gland cell; p. 15239. At this level of analysis connections are established by synapses (Foster & Sherrington, 1897). In normal, healthy animals qualitative aspects of microconnection patterns are genetically hardwired but their quantitative features can be modified by learning, stress, and a variety of other factors. more details

Micropathway : A pathway between two neurons (Waldeyer, 1891). more details

Midbrain ( MB ; Baer, 1837 ) : The middle of the three primary brain vesicles of the vertebrate neural tube (Baer, 1837) that develops into the adult midbrain (Baer, 1837), a topographic division between forebrain (Goette, 1873) and rhombicbrain (His, 1893b). Malpighi (1675; see translation by Adelmann, 1966, p. 1003) identified the cristate vesicle in the chick neural tube, and Baer named it the midbrain vesicle for embryonic vertebrates (1837, p. 106; in the original German, "mittlere Hirnbläachen"). Baer also named the corresponding adult structure the midbrain (1837, p. 107; in the original German, "Mittelhirn"). A synonym is the Latin mesencephalon (Sharpey et al., 1867). more details

Midline ( Aristotle ) : Synonym for median plane (Henle, 1855). Aristotle (Historia Animalium; see translation by Thompson, 1910, 491b-5) used (the Greek equivalent of) the term for macrodissected adult humans, translated "middle line". Also see Brusca & Brusca (1990, p. 46). more details

Midsagittal plane : Synonym for median plane (Henle, 1855); see Brusca & Brusca (1990, p. 46). more details

Mixed synapse : A synapse (Foster & Sherrington, 1897) that combines the features of both the chemical synapse and the electrical synapse; see Peters et al. (1991, pp. 207-210). more details

Motif : A recurring pattern of connections; that is, a unit chain from which more complex neural networks are constructed. A consensus motif is a recurring pattern of connections in a network of a specific type. more details

Myelencephalon ( Huxley, 1871 ) : Synonym for medulla (Winslow, 1733), pp. 59-60. Also see metencephalon (Huxley, 1871). more details

Myelencephalon ( Owen, 1868 ) : Synonym for vertebrate central nervous system (Meckel, 1817); pp. 266-268. more details

Myelin sheath : A covering of axons (Kölliker, 1896)-and occasionally dendrites (His, 1889) or even cell bodies (Deiters, 1865)-above a particular diameter characteristic for each species that speeds up action potential conduction velocity and is formed by types of glia (Virchow, 1846): oligodendrocyes in the vertebrate central nervous system (Meckel, 1817), and Schwann cells in the vertebrate peripheral nervous system (Meckel, 1817); see Williams (1995, pp. 951-954), Toesca (1996). The myelin sheath was probably discovered by Remak (1837) who described a very thin-walled tube around his primitive band, the axon; see Van der Loos (1967, p. 19). more details

Myelinated axon : An axon (Kölliker, 1896) with a myelin sheath, which is formed by types of glia (Virchow, 1846): oligodendrocyes in the vertebrate central nervous system (Meckel, 1817), and Schwann cells in the vertebrate peripheral nervous system (Meckel, 1817). Axons above a threshold diameter characteristic of particular species become myelinated, thus forming the set of thicker axons; see Williams (1995, pp. 951-954). The myelinated axon was probably discovered by Remak (1837) who described a primitive band-the axon-within a very thin-walled tube (see Van der Loos, 1967, p. 19). more details