FIG. 5.

Inhibition of JNK blocks BMP-dependent dendrite formation. (A) Primary cortical neurons expressing GFP were incubated with the JNK inhibitors, SP600125 at 20 μM in dimethyl sulfoxide (DMSO) or L-JNK1I, at 0.5 and 0.75 μM in the presence or absence of BMP7 for 48 h after 4 DIV. The number of dendrites per neuron in GFP-positive cells (A) that costained with the dendrite-specific Map2 (a+b) antibody (not shown) was determined. (B and C) Fold changes in dendrite numbers relative to the unstimulated GFP empty control are shown with 30 to 40 neurons analyzed per condition. Shown are the means ± the SEM of three (B) and two (C) independent experiments (P < 0.0001 and P < 0.05 [Student t test] for panels B and C, respectively). Scale bar, 20 μm.