Fig. 4.

Synapse formation and dendrite maturation in the Sema7A and PlxnC1 KOs. a Synapse markers within glomeruli in the Sema7A KO. OB sections of the WT and Sema7A KO at P5 and 8w were immunostained with antibodies against vGlut2 and GluR1, pre- and post-synaptic markers, respectively. Staining photos are shown for P5 sections. Signal intensities within the rI7 glomeruli were normalized by the pre-synaptic signals in the ONL and post synaptic signals in the EPL. Fluorescent signals of GL/ONL and GL/EPL in glomeruli are compared between the WT and Sema7A KO. Scale bars=25 μm. ^*p < 0.05, ^**p < 0.01 (Student’s t-test). Error bars indicate SD (n = 5, 6, 2, 3 animals). b Dendrite morphology of M/T cells in the Sema7A KO. EYFP-tagged rI7 glomeruli (green) were detected by immunostaining with anti-GFP antibodies. M/T cells (yellow) were visualized by Lucifer yellow (LY) injection into the rI7 glomeruli of the WT and Sema7A KO at P5 (left). The numbers of M/T cells with one dendrite (mature) and those with multiple dendrites (immature) to GL were counted for the rI7 glomeruli. The ratios (%) of mature (blue) and immature (white) M/T cells are shown (right): WT, 26/34 (76.5 %); KO, 8/34 cells (23.5 %). n = 20 glomeruli. Scale bar=10 μm. c Synapse markers within glomeruli in the PlxnC1 cKO. OB sections of the WT and PlxnC1 cKO at P5 and 8w were analyzed for synapse markers. Staining photos are shown for P5 sections. Signal intensities within the rI7 glomeruli were shown. Scale bars=25 μm. ^*p < 0.05, ^**p < 0.01 (Student’s t-test). Error bars indicate SD (n = 5, 5, 2, 3 animals). d Dendrite morphology in the PlxnC1 cKO. M/T cells (yellow) were visualized by LY injection into the rI7 glomeruli of the WT and PlxnC1 cKO at P5 (left). The ratios (%) of mature (blue) and immature (white) M/T cells are shown (right): WT, 24/31 (77.4 %); KO, 7/31 (22.6 %). n = 23 glomeruli. Scale bar=20 μm