Figure 3.

RNAi demonstration that β2*-nAChRs act cell-autonomously to elevate spine numbers. A, Labeled dendrites of cells expressing either β2-Scr (top) or β2-RNAi (bottom), injected intracranially on P1–P2 and imaged on P12 (arrows, spine examples). Scale bar, 10 μm. B, Spine counts per 20 μm dendrite of CA1 pyramidal neurons expressing the indicated RNAi constructs (n = 3–8 animals, 4–16 neurons per animal). C, Quantification of spines per dendritic length in β2KOs expressing the indicated construct. D, P4 slices infected with viral vectors expressing β2-RNAi or scRNAi and maintained for 7 d in culture before treating 1 h with 1 μm nicotine (Nic) or buffer (Buf) and quantifying spines (3–5 cells per culture; 6 cultures per condition).