Fig. 1.

Brain size was reduced in SREB2 Tg mice and increased in SREB2 KO mice. (a) Brain weight of SREB2 Tg and KO mice and their WT littermates (5 months old, n = 10). Body weight was as follows: Tg line, Male WT, 31.1 ± 2.8 g vs. Tg, 29.6 ± 1.3 g, P = 0.13; Female WT, 25.7 ± 0.9 g vs. Tg, 24.7 ± 0.8 g, P < 0.05; KO line, Male WT, 35.7 ± 2.5 g vs. KO, 31.3 ± 2.6 g, P < 0.01; Female WT, 28.2 ± 2.6 g vs. KO, 25.4 ± 4.4 g, P = 0.10. **, P < 0.01; ***, P < 0.001. (b) Representative magnetic resonance images of brains from SREB2 Tg mice, WT littermates (from a Tg line), and SREB2 KO mice. Parenchyma and ventricular volume was as follows: Tg line (5 months old, n = 6 male and 6 female), whole brain WT, 503 ± 43 mm³ vs. Tg, 403 ± 48 mm³, P < 0.001; cerebellum WT, 55.4 ± 4.3 mm³ vs. Tg, 53.3 ± 4.6 mm³, P = 0.27; ventricle WT, 2.11 ± 0.87 mm³ vs. Tg, 3.87 ± 2.2 mm³, P < 0.05; KO line (5 months old, n = 3 male and 3 female), whole brain WT, 484 ± 45 mm³ vs. KO, 555 ± 49 mm³, P < 0.05; cerebellum WT, 57.5 ± 6.2 mm³ vs. KO, 71.7 ± 3.3 mm³, P < 0.001; ventricle WT, 2.48 ± 0.78 mm³ vs. Tg 3.84 ± 1.99 mm³, P = 0.15. (c) Representative brain images of coronal sections from SREB2 Tg mice, WT littermates and SREB2 KO mice (5 months old, male). WT littermates derived from a Tg line were used. Sections were Nissl stained. Note that no gross malformation in SREB2 Tg and KO mice brains are seen. Yellow arrows show layers II/III in the sensory cortex. Neuronal soma size in the cortical area of SREB2 Tg mice was significantly smaller compared with that of WT littermates (averaged vertical length of 15 neurons from three subjects, WT, 13.7 ± 1.4 μm vs. Tg, 11.2 ± 1.1 μm, P < 0.01). Note that neuronal density in cortical layers II/III was higher in SREB2 Tg mice than in WT littermates. (d) Representative TUNEL images of forebrains from SREB2 Tg mice and WT littermates at postnatal day 10. SREB2 Tg mice showed a significant brain weight reduction during the critical developmental period (postnatal day 10, WT, 0.37 ± 0.01 g vs. Tg, 0.29 ± 0.01 g, P < 0.001, n = 3). Note that apoptotic neurons stained brown were excess in SREB2 Tg mice. (e) Representative Golgi staining images of hippocampal granular neurons from SREB2 Tg and WT littermates (10 months old, male). Note that fewer dendritic arborizations are seen in SREB2 Tg mice neurons. GL, granular layer of dentate gyrus; ML, molecular layer of dentate gyrus; SLM, stratum lacunosum-moleculare.