Figure 4.

Acute Rb removal in adult neurons triggers neuronal loss. A, TAM injection paradigm. B, Western blot of cortex lysates confirming the decrease of Rb levels in CamKCreERT2; Rb^flox/floxmice (Rb^f/f) 1 week after the last TAM injection. C, Rb loss results in neuronal loss in the cerebral cortex 4 weeks following TAM treatment (n = 3). D, E, Representative pictures of NeuN immunofluorescence displaying loss of neurons in the cortex of CamKCreERT2; Rb^flox/floxmice (E) compared with CamKCreERT2; Rb^flox/+mice (D). F, G, Ectopic expression of the proliferative marker Ki67 in NeuN⁺ neurons (arrows) of CamKCreERT2; Rb^flox/flox mice 1 week after the last TAM injection. H, Ectopically proliferating Ki67⁺ cells exhibit γ-H2AX immunoreactivity (arrows) following Rb deficiency. **p < 0.01,***p < 0.001. Scale bars: D, E, 100 μm; F–H, 50 μm. Error bars indicate SEM.