Fig. 6
From: Homeostatic plasticity shapes the visual system’s first synapse
Cell density regulates RBC axon and synapse development. a–c Maximum intensity projection of RBC axon terminals labeled by transgenic expression of tdTomato (Grm6 L -tdTomato in blue) and presynaptic release sites stained for the C-terminal binding protein 2 (CtBP2, red) in wild-type (a), Pcp2-DTA (b), and Pax6-DTA (c) retinas. For visual clarity, RBC axons and their synapses were digitally isolated in Amira. Scale bar indicates 5 μm. d–f Summary data of RBC axon surface areas in wild-type (d, n = 16 RBCs), Pcp2-DTA (e, n = 17 RBCs), and Pax6-DTA (f, n = 15 RBCs) mice. By Kruskal–Wallis one-way ANOVA testing, RBC axon surface areas in Pcp2-DTA and Pax6-DTA retinas were greater than in wild-type retinas (p < 0.02 and p < 10−8, respectively), and RBC axon surface areas were greater in Pax6-DTA than in Pcp2-DTA retinas (p < 0.003). g–i Population data (mean ± SEM) from wild-type (g, n = 16 RBCs), Pcp2-DTA (h, n = 17 RBCs), and Pax6-DTA (i, n = 15 RBCs) retinas show that synapse density tends to decrease with increasing axon size. By Kruskal–Wallis one-way ANOVA testing, RBC synapse densities in Pcp2-DTA and Pax6-DTA retinas were lower than in wild-type retinas (p < 0.003 and p < 0.02, respectively)
