SYNCHRONIZATION AND COORDINATION OF ADULT NEUROGENESIS DURING PREGNANCY

Adult neurogenesis is the process of generating new neuronal and glial cells in the adult brain from vestigial stem cells left behind from developmental times. These cells reside in tightly controlled environments called niches. Adult neurogenesis is evolutionary-conserved across vertebrates and plays a significant role in lifelong plasticity in the mammalian brain. In the mouse brain, there are two key neurogenic niches—the ventricular–subventricular zone (VSVZ) and the dentate gyrus (DG) of the hippocampus—where neural stem cells (NSCs) divide and generate new cells and circuits to constantly adapt to changing physiological conditions. Pregnancy is a physiological state characterized by a profound systemic change in many organs, including the brain. However, whether regionally distinct NSC pools across both niches coordinate their response to maintain stability while ensuring the necessary plasticity is still unknown. Taking into the account of heterogeneous nature of NSCs, both spatially and molecularly, we investigate how different niche sub-domains specifically respond to pregnancy and how this activation is tightly orchestrated. Combining immunostaining, high-resolution 2D and 3D imaging, as well as neuronal circuit tracing, this project aims first at identifying pregnancy-related synchronous niche domains. Second, we explore the hypothesis that distinct NSC sub-populations are co-regulated through long-range hypothalamic circuits involved in parenthood, lactation, and aggressiveness. Altogether, this work seeks to reveal how adult neurogenesis contributes to reshape the adult mammalian brain during pregnancy by generating new transient and/or long-lasting circuits in the olfactory bulb and hippocampus.