FIGURE 8.

Knockdown of RNG105 and RNG140 reduces spine density and affects the termination of axons from normal neurons to spines. A, cultured neurons were co-transfected with a GFP reporter and siRNA for control, RNG105, or RNG140. The neurons were then immunostained for presynaptic marker synapsin I. White arrowheads indicate postsynaptic spines of GFP-positive dendrites innervated by synapsin I-containing axon terminals from nontransfected GFP-negative neurons. Black arrowheads indicate spines without synapsin I staining. Scale bar, 10 μm. B, quantification of spine density, spine size, and fluorescence intensity of synapsin I on the GFP-positive spines in A. Rescue experiments also were performed. The fluorescence intensity of synapsin I on spines is normalized to that in GFP-negative areas in the same field. Spine density and synapsin I fluorescence intensity at spines were significantly reduced in RNG105 and RNG140 knockdown neurons. n = 6 for spine density. Numbers inside the bars are the number of spines analyzed. *, p < 0.05, **, p < 0.01, Student's t test. Error bars are S.E.