Serotonin (5-HT) plays an important role in regulating adult hippocampal neurogenesis. Chronic administration of selective 5-HT reuptake inhibitors (SSRIs), which up-regulates extracellular 5-HT concentration, accelerates the maturation of adult-born hippocampal neurons. It is unknown, however, about effects of central 5-HT-deficiency on the dendritic morphogenesis of these newborn neurons. Here, we address this question using two central 5-HT-deficient mouse models, Tph2 conditional knockout mice (CKO) losing central 5-HT from embryonic stage, and Pet1-Cre;Rosa26-DTR (diphtheria toxin receptor) mice lacking central 5-HT neurons exclusively in adulthood. The dendritic length of hippocampal newborn neurons is dramatically increased in these mice. Our findings indicate that reducing central 5-HT can accelerate the dendritic maturation of adult-born neurons, thus revealing a new role of central 5-HT in regulating adult hippocampal neurogenesis.
Song, N. N., Zhang, Q., Huang, Y., Chen, L., Ding, Y. Q., & Zhang, L. (2017). Enhanced dendritic morphogenesis of adult hippocampal newborn neurons in central 5-HT-deficient mice. Stem Cell Research, 19, 6–11. https://doi.org/10.1016/j.scr.2016.12.018