Article Figures & Data
Figures
- Figure 1.
Experience-dependent behavioral transition from attack to parenting in C57BL/6 male mice. A, Percentages of male mice exhibiting each behavior toward pups. Males' responses toward pups were categorized into four types: (1) parenting (PAR, white); (2) partial parenting (PP, light gray); (3) non-parenting (NP, dark gray); and (4) attack (ATK, black). The number of subjects in each group is shown above each bar. p < 0.001 (Fisher's exact test). B, Parental scores of individual mouse groups. The data are represented as the mean ± SEM. A Kuruskal–Wallis test revealed significant differences among groups (H(4) = 71.71, p < 0.001). ##p < 0.01, different from sexually naive males; **p < 0.01, different from all other groups (Steel–Dwass test).
- Figure 2.
c-Fos expression in the AOB neurons of sexually naive males and fathers after pup exposure. A–F, Representative microscopic images of c-Fos (black) and Gαo (brown) expression in the AOB of sexually naive males (A, C) and fathers (B, D) in control condition (A, B) and after pup exposure (C, D). E, F, Higher magnification of C and D. Scale bars, 100 μm. G–I, The numbers of c-Fos-positive cells in the glomerular layer (GL) (G), mitral/tufted cell layer (MCL) (H), and granule cell layer (GCL) (I) in the rostral and caudal zones of the AOB in sexually naive males and fathers with or without pup exposure (n = 6). Welch's ANOVA revealed significant differences among groups in both rostral and caudal zones of the GL (rostral, F(3,9.14) = 23.75, p < 0.001; caudal, F(3,9.89) = 7.37, p = 0.007), MCL (rostral, F(3,9.61) = 12.40, p = 0.001; caudal, F(3,10.58) = 4.58, p = 0.027), and GCL (rostral, F(3,10.09) = 7.59, p = 0.006; caudal, F(3,10.69) = 10.68, p = 0.002). Data are represented as mean ± SEM. *p < 0.05, **p < 0.01 (Welch's t test followed by correction with Holm's method). NS, Not significant.
- Figure 3.
c-Fos expression in higher brain regions in sexually naive males and fathers after pup exposure. A–P, Representative microscopic images of c-Fos expression. A–D, The dorsal (MePD) and ventral (MePV) subregions of the MeP. opt, Optic tract. E–H, The medial (BSTMPM), intermediate (BSTMPI), and lateral (BSTMPL) parts of the BSTMP. f, Fornix. I–L, MPA and the medial part of MPO (MPOM). ac, Anterior commissure; 3V, third ventricle. M–P, AH. Scale bars, 200 μm. Q–U, Quantification of c-Fos-positive cells in each region (n = 6). Welch's ANOVA revealed significant differences among groups in the MePD (F(3,10.58) = 26.93, p < 0.001), MePV (F(3,10.07) = 13.07, p = 0.01), BSTMPM (F(3,10.79) = 29.06, p < 0.001), BSTMPI (F(3,10.75) = 16.19, p < 0.001), BSTMPL (F(3,10.78) = 20.53, p < 0.001), MPOM (F(3,10.88) = 23.72, p < 0.001), MPOL (F(3,11.00) = 19.16, p < 0.001), MPA (F(3,10.79) = 16.93, p < 0.001), AH (F(3,11.05) = 7.54, p = 0.005), VMHC (F(3,10.44) = 13.99, p = 0.001), and VMHVL (F(3,10.66) = 3.68, p = 0.048) but not in VMHDM (F(3,10.48) = 0.31, p = 0.82). Data are represented as mean ± SEM. *p < 0.05, **p < 0.01 (Welch's t test followed by correction with Holm's method). MPOL, Lateral part of MPO; VMH, ventromedial hypothalamic nucleus; DM, dorsomedial; C, central; VL, ventrolateral.
- Figure 4.
A crucial role of the VNO in the attack-to-parenting transition in male mice. A–D, c-Fos expression (black) in VNO of sexually naive males (A, B) and fathers (C, D) in control condition (A, C) and after pup exposure (B, D). E–H, Double immunostaining of VNO section from sexually naive male mouse for c-Fos and Gαo. E, Gαo expression (green) in the same section as B. F, Merged image of B and E. White and black arrowheads denote c-Fos-positive/Gαo-negative and c-Fos-positive/Gαo-positive neurons, respectively. G, H, Enlarged views marked in F. I, Quantification of c-Fos-positive VSNs in sexually naive males and fathers with and without pup exposure (n = 6). Welch's ANOVA revealed a significant difference among groups (F(3,9.24) = 12.84, p = 0.001). Data are represented as mean ± SEM. **p < 0.01 (Welch's t test followed by correction with Holm's method). J–M, Surgical ablation of VNO. J, K, Coronal sections of the skulls from sham-operated (J) and VNO-ablated (VNOx) (K) mice stained with hematoxylin and eosin. L, M, Parasagittal sections of the AOB from sham-operated (L) and VNO-ablated (M) mice labeled with horseradish peroxidase-conjugated soybean agglutinin (brown). N, O, Effect of VNO ablation (blue in N, red in O) on the pup-directed behaviors in sexually naive males (N) and fathers (O). The number of subjects is shown on the graph. Males' behaviors toward pups are plotted as parental scores. **p < 0.01 (Mann–Whitney's U test). Scale bars: F, 50 μm; H, 10 μm; M, 200 μm.
