Figure 1.

Loss of Fmr1 disrupts the normal development of cell-to-cell connectivity mediated by AMPA:KA-Rs in L5a. A, Example traces from pre- (A1) and postsynaptic neurons (A2, A3, A4) demonstrating two connections of a possible three as observed by average uEPSCs. B–D, Connectivity frequency (B1, B2), frequency of connections being part of a “one-way” or “two-way” connection (C1, C2), and uEPSC amplitude (D1, D2) are plotted for WT (1) and Fmr1 KO (2) slices. Numbers in plots are total number of possible connections (B) and sample number (D). In C, #'s and *'s apply to one- vs two-way and P15 vs P30 comparisons, respectively. In D, medians are indicated. E, Percent change in connectivity (Conn) and median amplitude (Amp) in the P15→P30 interval. F, Replot of B for comparison between genotypes. *p < 0.05; **p < 0.01; ***p < 0.001 for all figures. Error bars in B, C, and F indicate 95% confidence interval.