Fig. 3: Long-term HMF exposure impaired the dendritic development of newborn neurons in the DG.

a Schematic diagram of the retroviral vector and stereotaxic grafting of retrovirus into the DG of adult mice. b Experiments timeline for the in vivo labeling and analyses of newborn neurons in the DG of GMF- and HMF-exposed mice. c Representative images of RFP⁺ newborn neurons in the DG of GMF- and HMF-exposed mice at 4-weeks post retrovirus injection. Scale bar = 50 μm. d, e Quantification of the dendritic length (d) and dendritic complexity (e, GMF versus HMF, UNIANOVA, F(1, 242) = 15.19 P < 0.001) of RFP⁺ newborn neurons in the adult DG of mice during 4-weeks GMF and HMF exposure. GMF, n = 167 neurons from four mice, HMF, n = 77 neurons from four mice. Data were analyzed by UNIANOVA analysis, and the two-tailed unpaired t test for two-group comparisons. f, g Quantification of the dendritic length (f) and dendritic complexity (g, GMF versus HMF, UNIANOVA, F(1, 131) = 10.76, P = 0.001) of RFP⁺ newborn neurons in the adult DG of mice during 12-weeks GMF and HMF exposure. GMF, n = 82 neurons from four mice, HMF, n = 50 neurons from four mice. Data were analyzed by UNIANOVA analysis, and the two-tailed unpaired t test for two-group comparisons. The data in (d, f) were presented in the whisker plot with defined elements, median (centerline), upper and lower quartiles (bounds of box), and highest and lowest values (whiskers). Other data are presented as mean ± SEM.