Figure 8

Inhibitory and excitatory synapse densities on RGC dendrites as a function of age. (A) Linear densities of YFP-NL2 puncta (shaded bars, n = number of cells) compared with the distribution of PSD95 (open bars) during development (data replotted from [14, 64]). (B) Centro-peripheral gradient of inhibitory and excitatory puncta obtained as described in Morgan et al. [14]. The gradients were quantified by determining the ratio of puncta density in the inner and outer halves of a circle encompassing 98% of the dendritic arbor. The analysis excludes a 10-μm region around the cell soma. The inner and outer densities were significantly different at all ages except for P12 (paired t-test; P < 0.05). (C) Ratio of average linear densities of YFP-NL2/PSD95-YFP across ages. Error bars are standard error of the means.