Figure 8.

Blebbistatin inhibits dendritic spine and synapse formation. A, Hippocampal neurons were treated with 50 μm blebbistatin at 7 d in culture and were fixed and immunostained for various synaptic markers at 9 d in culture. Control cultures were treated with DMSO. Arrows point to the abnormally long, thin, dendritic protrusions. Scale bar, 20 μm. B, Quantification of the number of synapses as visualized by both synapsin1 and PSD-95. ^*p < 0.0001. C, Quantification of the number of total protrusions, including dendritic spines and dendritic protrusions. ^*p < 0.0001. A total of 85-95 dendrites of 15-20 neurons from four independent cultures were analyzed for each condition. Error bars represent SEM from three experiments.