Figure S2. Nrg1 deletion by Cre expression in Nrg1 floxed cultured neurons and dendrite analysis.

(A) Representative pictures of a GFP-ires-Cre–expressing Nrg1^flox/flox neuron at DIV4. Naïve Nrg1^flox/flox neurons can be observed around the Nrg1 KO neuron, because of a positive DAPI staining and Nrg1 Type III labeling. Staining with the Nrg1 Type III–specific antibody confirms the Nrg1 deletion in our experimental setup (white arrowheads). Scale bar, 25 μm. (B) Representative images of control and Nrg1 KO neurons. (C) Concentric circles show the shells used for Sholl analysis in (C). Scale Bar, 50 μm. (C) Sholl analysis of the dendrite extension in control and Nrg1 KO neurons. Ctrl: n = 26; Nrg1 KO: n = 64, both out of three independent litters. Mixed-effects analysis with Sidak’s multiple comparisons test. Ctrl versus Nrg1 KO at 50 μm, #P < 0.05; ns, for the remaining shells, ***P < 0.001. Average ± SEM. (D) Quantification of axonal length in control and Nrg1 KO neurons shown in Fig 2, expressed in microns. Ctrl: n = 52; Nrg1 KO: n = 116, both out of three independent litters. Unpaired t test, ***P < 0.001.