Figure 3. IKKα inhibits the proliferation of early differentiating NPCs.

(A) Elevated IKKα accelerates NPCs commitment to differentiation. BrdU was added on the 4^th day of differentiation. 24 h later cells were fixed and stained with a rat anti-BrdU antibody (green) and the neuron-specific marker Tuj-1. Pictures were taken with a confocal microscope. (B) As a further test of proliferation, 4^th day cultures were stained with the Ki-67 antibody, which identifies proliferating cells. (C) A time-course (days) of BrdU incorporation reveals the difference in rate of decline in proliferation between the control and the IKKα+ NPCs. Each time point represents 24 h of BrdU incorporation. Samples were processed as in A.