Role of C/EBPβ Transcription Factor in Adult Hippocampal Neurogenesis

[Background]: The dentate gyrus of the hippocampus is one of the regions in which neurogenesis takes place in the adult brain. We have previously demonstrated that CCAAT/enhancer binding protein β (C/EBPβ) is expressed in the granular layer of the dentate gyrus of the adult mouse hippocampus. Taking into account the important role of C/EBPβ in the consolidation of long term memory, the fact that newborn neurons in the hippocampus contribute to learning and memory processes, and the role of this transcription factor, previously demonstrated by our group, in regulating neuronal differentiation, we speculated that this transcription factor could regulate stem/progenitor cells in this region of the brain. [Methodologu/Principal Findings]: Here, we show, using C/EBPβ knockout mice, that C/EBPβ expression is observed in the subset of newborn cells that proliferate in the hippocampus of the adult brain. Mice lacking C/EBPβ present reduced survival of newborn cells in the hippocampus, a decrease in the number of these cells that differentiate into neurons and a diminished number of cells that are proliferating in the subgranular zone of the dentate gyrus. These results were further confirmed in vitro. Neurosphere cultures from adult mice deficient in C/EBPβ present less proliferation and neuronal differentiation than neurospheres derived from wild type mice. [Conclusions/Significance]: In summary, using in vivo and in vitro strategies, we have identified C/EBPβ as a key player in the proliferation and survival of the new neurons produced in the adult mouse hippocampus. Our results support a novel role of C/EBPβ in the processes of adult hippocampal neurogenesis, providing new insights into the mechanisms that control neurogenesis in this region of the brain.This work was supported by a postdoctoral fellowship of the Consejo Superior de Investigaciones Cientificas (M.C.-C.) Grant Sponsor: Ministerio de Investigación y Ciencia; Grant numbers: SAF2007-62811 and SAF2010-16365. CIBERNED is funded by the Instituto de Salud Carlos III.Peer reviewe

You Need Guts to Make New Neurons

PURPOSE OF THE REVIEW: In the present review, we discuss the very recent findings that the gut microbiota composition can modulate cell-based plasticity in the brain, namely, adult hippocampal neurogenesis, and thereby alter hippocampal dependent behavior. RECENT FINDINGS: Absence of gut microbiota from birth or antibiotic-induced dysbiosis in adults leads to an aberrant metabolite production and immune functions. Both scenarios compromise a proper postnatal brain development, or brain wiring in adults, including aberrant neurogenesis. This in turn leads to a hippocampal mismanagement of environmental cues and renders the animals to be more susceptible to stress and less cognitively flexible which contribute to general impairments in learning and memory functions and social behavior. SUMMARY: Mounting evidence indicates that certain behavior aberrances in germ-free and dysbiotic mice are mediated by changes in neurogenesis. The mechanisms and the relevance of this complex regulation remain to be elucidated by future research