title: [MicroRNAs in neurobiology].
abstract: MicroRNAs have emerged as a new regulatory factor of gene expression. They mediate translational repression or degradation of their target mRNAs by RNA interference (RNAi). The expression of each microRNA is tightly regulated in a development- and cell-specific manner by various mechanisms such as blockade of let-7 family expression by Lin-28 or RNA editing. They also act as regulatory switches for development, organogenesis, and cellular differentiation or for controlling distinct functions that are required for the maintenance of each tissue and cell subtypes. The abundant expression of microRNAs as well as the exclusive expression of certain microRNAs in the central nervous system highlights their biological importance at all stages of neural development and in postmitotic and differentiated neurons. Further, some microRNAs, such as miRNA-134, and miRNA-132 are localized and are synthesized in part at synaptic sites in dendrites to regulate synaptic formation and plasticity. In addition to the imparting of basic knowledge about the biogenesis and mechanism of action of microRNAs, this review focuses on the recent advances in microRNA studies in neurobiology, including the expression pattern of microRNAs in the mammalian brain, the role of microRNAs in neural differentiation and maturation, formation and plasticity of synaptic connections, and maintenance of neural function such as the synthesis of the neurotransmitters in selected neurons. Finally, the possible connection between microRNA dysfunction and neurological diseases, and future implications for diagnosis, and treatment of defects in human brain development and neurodegenerative diseases are discussed.
authors.affiliation: Wistar Institute, Philadelphia, Pennsylvania 19104, USA.
authors.forename: Yukio
authors.initials: Y
authors.lastname: Kawahara
mesh_terms: D000818:Animals; D005786:Gene Expression Regulation / Q000235:genetics; D006801:Humans; D035683:MicroRNAs / Q000502:physiology; D009410:Nerve Degeneration / Q000235:genetics; D009446:Neurobiology; D055495:Neurogenesis / Q000235:genetics; D014176:Protein Biosynthesis / Q000235:genetics; D017393:RNA Editing / Q000235:genetics; D034622:RNA Interference; D016601:RNA-Binding Proteins / Q000502:physiology
chemical_list: C000715187:Lin28A protein, human; D035683:MicroRNAs; D016601:RNA-Binding Proteins; C487931:mirnlet7 microRNA, human