It can be used by not only the community to assess their development progress but also the government to find references for its policy making.Conflict selleck catalog of InterestsThere is no conflict of interests regarding the publication of this paper.AcknowledgmentsThe authors hereby would like to express their gratitude to the Dahu Community in Kaohsiung city for funding this study (Zihao-Dahu Community Mei Zihao-100122 and Mei Zihao- 102214��Love for the Earth, Let us Go!) and all its assistance.
miRNAs are a group of single-stranded small noncoding RNA molecules with 19�C22 nucleotides, which could posttranscriptionally degrade mRNA or inhibit the translation of mRNA via binding the untranslated region at 3�� end of target mRNA and furthermore influence the expression of target genes.

miRNA genes are usually transcribed by RNA polymerases II and III. With the presence of enzyme Drosha, pri-miRNA is synthesized and then cut into pre-miRNA with hairpin by Drosha. In the cytoplasm, the pre-miRNA hairpin is cleaved into double-stranded miRNA by the RNase III enzyme Dicer. One of the mature single-stranded miRNAs is kept in the silencing complex and may cleave target mRNA via binding to the complementary 3��-untranslated region (3��-UTR) in the target gene, resulting in posttranscriptional silencing [3�C5]. Since Rota et al. found the first miRNA (lin-4) in nematodes in 1993, more than 1400 miRNAs have been identified in mammalians [6]. miRNAs play important roles in the gene regulation and more than 50% of genes in mammalians are regulated by miRNAs [7].

Previous studies have demonstrated that miRNAs play important roles in multiple physiological and pathological processes. It has been shown that the functional disorder of miRNAs is closely related to some pathological processes of central nervous system including stroke, multiple sclerosis, temporal lobe epilepsy, Alzheimer’s disease, schizophrenia, and bacterial meningitis [8].Some miRNAs are associated with the development of the brain, differentiation of neurons, and advanced neurological functions (such as learning and memory) and play important roles in maintaining survival of mature neurons and regulating development and differentiation of neurons. miRNAs have been identified in zygotes, neural stem cells, and fetal brain [9]. The deficiency of miRNAs in the cerebral cortex and hippocampus may significantly influence the morphogenesis of neurons and brain [10].

Experimental introduction of miR-430 may partially reverse the abnormal morphogenesis due to miRNA deficiency [11]. miRNAs could regulate cell cycle and play crucial roles in the Brefeldin_A regulation of neuronal differentiation. MiR-132, -134, and -let-7 are also crucial for the formation and plasticity of synapses [12]. miR-1 and miR-133 may exert regulatory effects on the synaptic transmission at the neuromuscular junction [13]. In addition, miR-124a and miR-125b may also promote the outgrowth of axons [14].