Fig 2

(A, B) IHC for S100β and PCNA in control (A) and 5-HT-injected (B) brains. (C) Quantification of proliferating glia in conditions of panels A and B. (D, E) IHC for BrdU and HuC/D for newborn neurons at 14 dpi after BrdU treatment at 2 and 3 dpi (D) and BDNF injection (E). (F) Quantification of newborn neurons. (G) IHC for GFP (driven by glial promoter her4.1) and PCNA in control, IL4-injected, Aβ42-injected, and 5-HT-injected brains. (H) Quantification of proliferating glia in conditions of panel G. (I-K) IHC for her4.1-driven GFP and 5-HT. The composite image (I) and single fluorescent channels for her4.1:GFP (J) and 5-HT (K). (L) ISH for htr1a (panel Lʹ: close-up image of framed region in panel L). (M) ISH for htr1d (panel Mʹ: close-up image of framed region in panel M). (N) IHC for pERK and her4.1-driven GFP in control and 5-HT-injected brains. (O) Quantification of pERK-positive periventricular neurons. (P) Working hypothesis on the indirect regulation of 5-HT on NSC plasticity. n = 4 animals for experiments. Scale bars equal 100 μM. Data are represented as mean ± SEM. See also S3 Fig. See S7 Data for supporting information. Aβ42, amyloid-beta42; BDNF, brain-derived neurotrophic factor; BrdU, 5-bromo-2'-deoxyuridine; dpi, days post injection; GFP, green fluorescent protein; HTR1, 5-hydroxytryptamine receptor 1; HuC/D, ELAV (embryonic lethal, abnormal vision, Drosophila)-like 3/4; IHC, immunohistochemistry; IL4, interleukin-4; ISH, in situ hybridization; NSC, neural stem cell; pERK,; phosphorylated extracellular signal-regulated kinase; PCNA, proliferating cell nuclear antigen; PVZ, periventricular zone; S100β, S100 calcium-binding protein B; 5-HT, serotonin.