Juan Song, PhD
Assistant Professor of Pharmacology and
Primary Member UNC Neuroscience Center
University of North Carolina at Chapel Hill
Host: Aaron Gitler
A growing body of data in many tissue systems indicates that stem cell function is critically influenced by the microenvironment in which stem cells reside. Therefore, the stem cell niche represents a critical entry point for therapeutic modulation of stem cell behavior. In addition to classic niche factors described for other somatic stem cell compartments, such as morphogens and growth factors, dynamic regulation by ongoing network activity is a hallmark of adult neurogenesis. Neural stem cells (NSCs) and their progeny reside in a specialized local environment within the dentate gyrus (DG) that consists of a diverse group of local cells with distinct molecular, morphological, and functional properties, and signaling from these local cells can potentially control the NSC niche activity and key behavior of NSCs. Despite lacking synapses, NSCs “listen to” the neural network and take proper actions in response to ongoing network activity. For instance, our recent studies identified local parvalbumin-expressing (PV) interneurons and mossy cells (MCs) as critical niche cells in regulating DG network activity and the key behaviors of NSCs in vivo. While DG PV interneurons and MCs release GABA and glutamate as their main neurotransmitters, respectively, many local interneurons and long-distance projection neurons also release neuromodulators that could exert broad and long-lasting actions on multiple types of local niche cells. I will discuss our recent findings on how distinct neural circuits regulate adult NSCs and how NSCs interpret diverse niche signals from the local environment to make the ultimate decision to stay in quiescence or become activated.
 Hechen Bao, Brent Asrican, Weidong Li, ..., Karl Deisseroth, Benjamin Philpot, Juan Song. Long-range GABAergic inputs regulate neurl stem cell quiescence and control adult hippocampal neurogenesis. 2017 Cell Stem Cell 21(5):604-617 (Cover article, featured article, recommended by F1000, selected as one of the best articles in Cell Stem Cell in 2017) November 2, 2017. DOI: 10.1016/j.stem.2017.10.003
 Chia-Yu Yeh, Brent Asrican, Jonathan Moss, Luis Jhoan Quintanilla, Ting He, Xia Mao, Frederic Casse, Elias Gebara, Hechen Bao, Wei Lu, Nicolas Toni, Juan Song. Mossy cells control adult neural stem cell quiescence and maintenance through a dynamic balance between direct and indirect pathways. Neuron, Volume 99, Issue 3, 8 August 2018, Pages 425-427 (Featured article, issue highlights). DOI: 10.1016/j.neuron.2018.07.010