Fig. 4.
Presynaptic GABA content in juvenile (PND10-14) striatal D1R-MSNs is increased upon decreased Foxp2 expression. a Example traces of vesicle depletion following train stimulation (10 Hz, 100 stimuli) in Foxp2+/+ and Foxp2S321X/+ D1R-MSNs, every 10th response is shown. Scale 100 ms/50 pA. b Normalized (to first pulse) IPSC response during train stimulation. c Cumulative IPSC amplitude during train stimulation of D1R MSNs, (Foxp2+/+ = intercept 294.24 ± 85.3 pA, cumulative 3112.9 ± 286.4 pA, Foxp2S321X/+ = intercept 498.9 ± 301.3 pA, cumulative 5142.1 ± 484.6 pA, P < 0.001, two-sided Student’s T test). N number of mice, n number of cells. Foxp2+/+ N/n = 3/16, Foxp2S321X/+ N/n = 3/16. d Example trace of excitatory PPR at different inter stimulus intervals (ISI) in D1R-MSNs of Foxp2+/+ and Foxp2S321X/+ mice. Scale 100 ms/50 pA. Quantification of paired pulse ratio (PPR) (50, 100, 150, 200, 500ms: Foxp2+/+ 1.573 ± 0.08, 1.284 ± 0.06, 0.958 ± 0.02, 0.955 ± 0.04, 0.856 ± 0.02 vs Foxp2S321X/+ 1.864 ± 0.13, 1.357 ± 0.1, 1.244 ± 0.1, 1.131 ± 0.06, 0.884 ± 0.04, NS, Repeated measures ANOVA). Foxp2+/+ N/n = 2/8, Foxp2S321X/+ N/n = 3/11. e Same as d but for inhibitory PPR, (50, 100, 150, 200, 500 ms: Foxp2+/+ 0.936 ± 0.05, 0.872 ± 0.05, 0.832 ± 0.04, 0.798 ± 0.04, 0.718 ± 0.03 vs Foxp2S321X/+ 0.983 ± 0.06, 0.973 ± 0.07, 1.016 ± 0.05, 0.947 ± 0.03, 0.894 ± 0.04. P < 0.001 for 150, 200, 500 ms, repeated measures ANOVA). Foxp2+/+ N/n = 3/23, Foxp2S321X/+ N/n = 3/20. PPR is normalized to the first pulse. f Example trace of postsynaptic inhibitory response to forced vesicle exocytosis during 10 s local application of 500 mM sucrose. Scale 2 s/50 pA. Normalized (to wild-type) current transfer during 10 s sucrose application (Foxp2+/+ = 9.1 × 105 ± 1.26 × 105 pA, Foxp2S321X/+ = 13.4 × 105 ± 1.6 × 105 pA, P < 0.01, two-sided Students’ T test). Foxp2+/+ N/n = 2/15, Foxp2S321X/+ N/n = 3/16. g Example trace of postsynaptic response during 10 s local application of 100 µM GABA. Scale 2 s/200 pA. Quantification of peak amplitude and total current transfer during GABA application (Foxp2+/+ = 1.00 × 103 ± 66.7 pA, Foxp2S321X/+ = 1.04 × 103 ± 125 pA, NS, total current transfer Foxp2+/+ = 4.8 × 106 ± 3.4 × 105 pA, Foxp2S321X/+ = 5.4 × 106 ± 5.5 × 105 pA, NS, two-sided Student’s T test). Foxp2+/+ N/n = 2/14, Foxp2S321X/+ N/n = 2/12. *P < 0.05, ***P < 0.001