Figure 7.

P2 hippocampal neurons grown in vitro for 18 days display a mature phenotype with clear differentiation of axons labeled with SMI 31 and dendrites labeled with MAP2 (A, top panel) and formation of extensive synaptic contacts labeled with synaptophysin on MAP2 dendrites (A, middle panel) and Asyn immunostaining distributed along MAP2 positive and negative neurites (A, bottom panel). Figure enlargement shows Asyn-positive (green) in a punctuate pattern on dendrites. Scale bar = 20 μm. Hippocampal neurons (DIV 16) treated with C3 transferase (5 μg/ml) for 48h causes a reduction in Asyn protein in cell lysates as compared to control (B). Transfection with HSV-vector vC3t expressing C3 transferase but not with control vector vGFP (MOI 1) for 48h also causes reduction of Asyn protein (C). Treatment with SRF siRNA 1μM for 72h caused a marked reduction in SRF protein that was accompanied by a decreased in GATA2 transcription factor and Asyn levels. These changes were not seen in neurons treated with csiRNA for 72h. Results are representative of at least three independent experiments. Each sample was calculated as a ratio to β-actin and presented as percentage of control. Mean ± SEM; *p< 0.05, **p<0.01, ***p<0.005