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In neuroanatomy and neuroembryology, a ganglionic eminence (GE) is a transitory brain structure that guides cell and axon migration.〔 It is present in the embryonic and fetal stages of neural development found between the thalamus and caudate nucleus.〔Encha-Razavi & Sonigo. (2003). Features of the developing brain. ''Child's Nervous System''. pp. 426-428〕 The eminences are found in the ventral ventricular zone of the telencephalon, where they facilitate tangential cell migration during embryonic development. Tangential migration does not involve interactions with radial glial cells, instead the interneurons migrate perpendicularly through the radial glial cells to reach their final location. The characteristics and function of the cells that follow the tangential migration pathway seem to be closely related to the location and precise timing of their production.〔Marín & Rubenstein. (2001). A Long, Remarkable Journey: Tangential Migration in the Telencephalon. ''Nature Reviews Neuroscience, 2''.〕 GABAergic interneurons migrate tangentially, and the GEs contribute significantly to building up the GABAergic cortical cell population.〔〔Ghashghaei, H., Lai, C., & Anton, E. (2007). Neuronal migration in the adult brain: Are we there yet? ''Nature Reviews Neuroscience, 8.'' pp. 141-151.〕〔Hernández-Miranda, Parnavelas, & Chiara. (2010). Molecules & mechanisms involved in the generation and migration of cortical interneurons. ''ASN Neuro, 2''(2). pp. 75-86.〕 Another structure that the GEs contribute to is the basal ganglia. The GEs also guide the axons growing from the thalamus into the cortex and vice versa. In humans, the GEs disappear by one year of age.〔 During development, neuronal migration continues until the extinction of the germ layer, at which point the remnants from the germ layer make up the eminences.〔 ==Categorization== Ganglionic eminences are categorized into three groups based on their location within the subventricular zone: * Medial ganglionic eminence (MGE) * Lateral ganglionic eminence (LGE) * Caudal ganglionic eminence (CGE)〔Brazel, Romanko, Rothstein, Levison. (2003). Roles of the mammalian subventricular zone in brain development. ''Progress in Neurobiology, 69,'' p.49-69. doi 10.1016/S0301-0082(03)00002-9.〕 A sulcus separates the medial and lateral ganglionic eminences. The expression of ''Nkx2-1'', ''Gsx2'', and ''Pax6'' is required to determine the independent progenitor cell populations in the LGE and MGE. Interactions between these three genes define the boundaries between the different progenitor zones and mutations of these genes can cause abnormal expansion around the MGE, LGE, ventral pallium (VP), and anterior entopeduncular region (AEP). The cells of the GEs are quite homogenous, with the MGE, LGE, and CGE all having small, dark, irregular nuclei and moderately dense cytoplasm, however, each eminence can be identified by the type of progeny that it produces.〔 See the individual GE sections below for more information on the different types of progeny produced. Additionally, the subventricular zone is the starting point of multiple streams of tangentially migrating interneurons that express ''Dlx'' genes. There are three main tangential migration pathways that have been identified in this region: # the latero-caudal migration (subpallial telencephalon to cortex) # the medio-rostral migration (subpallial basal telencephalon to the olfactory bulb) # the latero-caudal migration (basal telencephalon to the striatum) These pathways are temporally and spatially distinct, and produce a variety of GABAergic, and non-GABAergic interneurons. One example of GABAergic interneurons that the GEs guide are parvalbumin-containing interneurons in the neocortex. Some examples of non-GABAergic interneurons that the GEs guide are dopaminergic interneurons in the olfactory bulb, and cholinergic interneurons in the striatum. Cells migrating along these pathways move at different rates. Some molecules that have been implicated in controlling the rate of the unidirectional movement of cells derived from the GEs are hepatocyte growth factor/scattered factor (HGF/SF), and variousneurotrophic factors.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Ganglionic eminence」の詳細全文を読む スポンサード リンク
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