FIGURE 1.

Neurons treated with SPARC have increased GluA1 but not GluA2 surface expression. Representative images of surface GluA1 (A) and GluA2 (B) expression showing increased intensity of GluA1 puncta in 14 DIV hippocampal neuron cultures treated with SPARC (0.5 μg/ml, 48 h) (A) but no change in GluA2 (B) vs. control cultures. The boxed region is magnified below each image [Student’s t-test, ^∗p = 0.0005 (n = 3)]. (C) Representative immunoblots showing cell surface (left panel) and total GluA1 and GluA2 (right panel) levels in control cultures and cultures treated with SPARC (0.5 μg/ml, 48 h). Cell surface receptor levels were determined by cell surface biotinylation. Neurons cultured with SPARC had significantly higher surface GluA1 but not GluA2 [2-tailed, 1-sample t-test; p = 0.03, n = 3)] levels without an increase in total receptor levels (D).