Fig. 7. NTF-dependent axonal growth at 40 hours in culture. (A) Treatment with NRTN and NGF (100 ng/ml each) does not increase significantly axonal growth at 40 hours in culture compared with the control. Roscovitine (Rosc) blocks axonal growth at 40 hours in the absence of NTFs (A,B,D) but fails to affect outgrowth in sister cultures treated with NTFs (A,C,E). Simultaneous treatment with roscovitine and SU6656 (SU) inhibits axonal growth (A). Roscovitine was applied at 50 µM, SU6656 at 2 µM. (B,C) The schemes show which elements of the network are active (bright colors) according to the model and which elements are inactive (faint colors), under particular conditions. Bars, 20 µm.