Figure 4.

Overexpression of SAP97 with WT GluR1 (but not GluR1Δ7) leads to synergistic dendrite growth-promoting effects. Top, Representative camera lucida images of neurons expressing GFP alone, SAP97 alone, WT GluR1 + SAP97, and GluR1Δ7 + SAP97. Scale bar, 35 μm. Bottom, The chart provides quantitative analysis of dendrites as well as statistical analysis using ANOVA. The number of neurons drawn is noted in parentheses next to the column title. There is a statistically significant increase in branching when SAP97 is expressed in neurons compared with GFP-expressing neurons. Coexpression of WT GluR1 + SAP97 leads to a marked increase in dendrite branching as well as increase in overall arbor size and average length of dendrites. This growth-promoting effect was not seen when GluR1Δ7 was coexpressed with SAP97.