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A Neuronal lineage marker is an endogenous tag that is expressed in different cells along neurogenesis and differentiated cells as neurons. It allows detection and identification of cells by using different techniques. A neuronal lineage marker can be either DNA, mRNA or RNA expressed in a cell of interest. It can also be a protein tag, as a partial protein, a protein or a epitope that discriminates between different cell types or different states of a common cell. An ideal marker is specific to a given cell type in normal conditions and/or during injury. Cell markers are very valuable tools for examining the function of cells in normal conditions as well as during disease. The discovery of various proteins specific to certain cells led to the production of cell-type-specific antibodies that have been used to identify cells.〔Redwine, J. M., & Evans, C. F. (2002). Markers of central nervous system glia and neurons in vivo during normal and pathological conditions. Current Topics in Microbiology and Immunology, 265, 119–40.〕 The techniques used for its detection can be immunohistochemistry, immunocytochemistry, methods that utilize transcriptional modulators and site-specific recombinases to label specific neuronal population,〔Jefferis G, Livet J. Sparse and combinatorial neuron labelling. Curr Opin Neurobiol. 2012;22:101-10〕 in situ hybridization or fluorescence in situ hybridization (FISH).〔Swanger SA, Bassell GJ, Gross C. 2011. High-resolution fluorescence in situ hybridization to detect mRNAs in neuronal compartments in vitro and in vivo. Methods Mol Biol 714:103–123.〕 A neuronal lineage marker can be a neuronal antigen that is recognized by an autoantibody for example Hu, which is highly restricted to neuronal nuclei. By immunohistochemistry, anti-Hu stains the nuclei of neurons.〔Graus, F., & Ferrer, I. (1990). Analysis of a neuronal antigen (Hu) expression in the developing rat brain detected by autoantibodies from patients with paraneoplastic encephalomyelitis. Neuroscience Letters, 112(1), 14–18. doi:10.1016/0304-3940(90)90314-Y〕 To localize mRNA in brain tissue, one can use a fragment of DNA or RNA as a neuronal lineage marker, a hybridization probe that detects the presence of nucleotide sequences that are complementary to the sequence in the probe. This technique is known as in situ hybridization. Its application have been carried out in all different tissues, but particularly useful in neuroscience. Using this technique, it is possible to locate gene expression to specific cell types in specific regions and observe how changes in this distribution occur throughout the development and correlate with the behavioral manipulations.〔Wuenschell, C. W., Fisher, R. S., Kaufman, D. L., & Tobin, a J. (1986). In situ hybridization to localize mRNA encoding the neurotransmitter synthetic enzyme glutamate decarboxylase in mouse cerebellum. Proceedings of the National Academy of Sciences of the United States of America, 83(16), 6193–7.〕 Although immunohistochemistry is the staple methodology for identifying neuronal cell types, since it is relatively low in cost and a wide range of immunohistochemical markers are available to help distinguish the phenotype of cells in the brain, sometimes it is time-consuming to produce a good antibody.〔Islam, M.R. (2007). In situ hybridization histochemistry: a novel method for neuronal tissues study. Bangl. J. Vet. Med. (2007). 5 (1 & 2): 111–114〕 Therefore, one of the most convenient methods for the rapid assessment of the expression of a cloned ion channel could be in situ hybridization histochemistry. After cells are isolated from tissue or differentiated from pluripotent precursors, the resulting population needs to be characterized to confirm whether the target population has been obtained. Depending on the goal of a particular study, one can use neural stem cells markers, neural progenitor cell markers, neuron markers or PNS neuronal markers. ==History== The study of the nervous system dates back to ancient Egypt but only in the ninetieth century it became more detailed. With the invention of the microscope and a technique of staining developed by Camillo Golgi, it was possible to study individual neurons. This scientist started to impregnate nervous tissue with metal, as silver. The reaction consists in fixing particles of silver chromate to the neurilemma, and resulted in a stark black deposit in the soma, axon and dendrites of the neuron. Thus, it was possible to identify different types of neurons, as Golgi Cell, Golgi I and Golgi II.〔(【引用サイトリンク】title=Life and Discoveries of Camillo Golgi )〕 In 1885 there was a German medical researcher called Franz Nissl who developed another staining technique now known by Nissl staining. This technique is slightly different from Golgi staining since it stains the cell body and the endoplasmic reticulum.〔(【引用サイトリンク】title=Whonamedit - Franz Nissl )〕 In 1887, a Spanish scientist called Santiago Ramon y Cajal learned the staining technique with Golgi and started his famous work of neuroanatomy.〔Sherrington, C. S. (1935). "Santiago Ramon y Cajal. 1852–1934". Obituary Notices of Fellows of the Royal Society 1 (4): 424.〕 With this technique he made an extensive study of several areas of the brain and in different species. He also described very precisely the purkinje cells, the chick cerebellum and the neuronal circuit of the rodent hippocampus. In 1941 Dr. Albert Coons used for the first time a revolutionary technique that uses the principle of antibodies binding specifically to antigens in the tissues. He created an immunoflorescent technique for labelling the antibodies.〔(【引用サイトリンク】title=Albert Hewett Coons, June 28, 1912—September 30, 1978 | By Hugh O. McDevitt | Biographical Memoirs )〕 This technique continues to be widely used in neuroscience studies for identifying different structures. The most important neural markers used nowadays are the GFAB, Nestin, NeuroD antibodies and others.〔 For the past years there are still creating new neural markers for immunocytochemistry or/and immunohistochemistry. In 1953 Heinrich Klüver invented a new staining technique called, Luxol Fast Blue stain or LFB, and with this technique it’s possible to detect demyelination in the central nervous system. Myelin sheath will be stained blue, but other structures will be stained as well. The next revolutionary technique was invented in 1969 by an American scientist called Joseph G. Gall.〔Gall, J., & Pardue, M. (1969). Formation and detection of RNA-DNA hybrid molecules in cytological preparations. … of the National Academy of Sciences, (1), 378–383. Retrieved from http://www.pnas.org/content/63/2/378.short〕 This technique is called in situ Hybridization and it is used in a large variety of studies but mainly used in developmental biology. With this technique it is possible to mark some genes expressed in determined areas of the animal. In neurobiology, it's very useful for understanding the formation of the nervous system. 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「Neuronal lineage marker」の詳細全文を読む スポンサード リンク
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