The level of cortical mTOR activity in postnatal, young adult mice and after postnatal rapamycin treatment. A, Representative coronal sections of motor cortex from P7 and P35 mice stained with p-S6 and NeuN antibodies. A′, Higher-magnification of the boxed areas in A. B, Coronal sections of motor cortex from mice subjected to P7 pyramidotomy stained with p-S6 and NeuN antibodies. Animals received either vehicle or rapamycin treatment and were perfused at 4 weeks after pyramidotomy. Scale bars: A, 500 μm; A′, 100 μm; B, 50 μm.