microRNA-Mediated Regulation of Adult Hippocampal Neurogenesis; Implications for Hippocampus-dependent Cognition and Related Disorders?

Abstract The adult hippocampus contains neural stem/progenitor cells (NSPC) that proliferate and differentiate to generate new neurons across the lifespan of most mammalians in a process, termed “adult neurogenesis.” This process takes place within a characteristic local microenvironment where NSPC interact with a variety of other cell types and encounter systemic regulatory factors, known as the adult hippocampal neurogenic niche. Within this microenvironment, cell-intrinsic gene expression programs are modulated by cell-extrinsic signals through complex interactions, in many cases involving epigenetic mechanisms. In this chapter, we will review the regulation of gene expression by microRNAs in NSPC and other cell types within the adult hippocampal neurogenic niche and its possible implications for neurodegenerative diseases such as Epilepsy and Alzheimer’s, which have been linked to alterations in adult hippocampal neurogenesis, with special focus on their associated cognitive impairment.