New Insights: MicroRNA Function in CNS Development and Psychiatric Diseases

Purpose of Review: Here, we concisely review microRNA (miRNA)-related research publications on the central nervous system (CNS) development (focusing on the forebrain and the cerebellum) and related psychiatric diseases over the past 3 years. We intend to summarize the new insights from these publications and, at the same time, provide personal views on some of the important mechanistic questions in the field. Recent Findings: MiRNAs, a type of small non-coding RNA molecules, have emerged as essential players in many biological processes. During CNS development, miRNAs have also been shown to exert their posttranscriptional regulation in numerous developmental events acting from master regulators to fine tuners of gene expression. While a single miRNA miR-980 regulates neuronal excitability and leads to alterations in behaviors associated with memory, sometimes multiple miRNAs have to functionally converge to induce one developmental process. Recent findings identified novel target genes for selected miRNAs during distinct developmental processes, and highlighted their important functions in several signaling pathways. Meanwhile, abnormal function of miRNAs during CNS development could lead to psychiatric diseases later on in life. Indeed, genomic variants, microdeletion, and microduplication could directly or indirectly involve miRNAs in the onset of these psychiatric diseases. Summary: Over the years, substantial research discoveries have been made to uncover molecular mechanisms of miRNA action, especially in the CNS, during normal development and under disease conditions. Thorough understanding of miRNAs function during these biological processes will facilitate future therapeutic interventions with this small, chemically synthesizable RNA molecules.