Figure 2.

Rapamycin can prevent or reverse macrocephaly in Pten mutant mice. A, Rapamycin injection strategy. Rapamycin was applied to two cohorts of mice at different ages: a young group (5–6 weeks old) and an adult group (10–12 weeks old). Mutants and controls injected with either vehicle or 10 mg/kg rapamycin were analyzed after 4 or 6 weeks of injections. B, Rapamycin prevents or reverses the brain enlargement of Pten mutant mice. The effect of rapamycin on brain and body weight was measured after 4 weeks for the young group or after 6 weeks for the adult group (n = 15 mice per group for body weight measurement, n = 8 mice per group for brain/body ratio). Data are mean ± SEM and were analyzed by paired t test. *p < 0.05 and **p < 0.01 compared with control mice treated with vehicle or between groups as indicated. C, Representative Nissl staining shows that rapamycin (Rapa) treatment suppressed the enlargement of the cortex (scale bar, 200 μm) and hippocampus (scale bar, 500 μm) when applied to young Pten mutant mice for 4 weeks. Arrows show thickness of cortical layers II–VI.