Pregnancy-responsive pools of adult neural stem cells for transient neurogenesis in mothers

Adult neural stem cells (NSCs) contribute to lifelong brain plasticity. In the adult mouse ventricular-subventricular zone, NSCs are heterogeneous and, depending on their location in the niche, give rise to different subtypes of olfactory bulb (OB) interneurons. Here, we show that multiple regionally distinct NSCs, including domains that are usually quiescent, are recruited on different gestation days during pregnancy. Synchronized activation of these adult NSC pools generates transient waves of short-lived OB interneurons, especially in layers with less neurogenesis under homeostasis. Using spatial transcriptomics, we identified molecular markers of pregnancy-associated interneurons and showed that some subsets are temporarily needed for own pup recognition. Thus, pregnancy triggers transient yet behaviorally relevant neurogenesis, highlighting the physiological relevance of adult stem cell heterogeneity. Different subtypes of new neurons are born in the adult brain ventricular-subventricular zone from spatially distinct pools of neural stem cells (NSCs). However, the physiological relevance of NSC diversity and specificity is unclear. Chaker et al . have revealed that during mouse pregnancy, multiple NSC pools are activated in mothers and generate specific olfactory bulb interneurons that function around birth to modulate aspects of maternal care, including own-pup recognition, and then disappear as pups mature (see the Perspective by Kempermann). These results highlight how adult NSC heterogeneity might provide a substrate for adaptive brain plasticity in response to different physiological states. —Mattia Maroso Dynamic response of adult neural stem cells during pregnancy prepares the maternal olfactory bulb for motherhood.