Figure 4. Retinogeniculate inputs to TC neurons in D2 mice. A, Recording schematic of optic tract (OT) with stimulating electrode, ventral lateral geniculate nucleus (vLGN), and dLGN with patch clamp electrode in parasagittal slice. B, Example maximal AMPA-receptor-mediated and NMDA-receptor-mediated EPSCs recorded at −70 and +40 mV, respectively, following maximal stimulation of the optic tract with a pair of pulses (200-ms interstimulus interval). C, Group data of the AMPA-receptor-mediated maximal EPSC (EPSCAMPA) show that the EPSC differed among the groups (nested one-way ANOVA, F(3,36) = 11.23, p = 2.4 × 10−5). The EPSCAMPA was significantly smaller in amplitude in recordings from 12m D2 mice compared with controls (Dunnett’s multiple comparison test: 6m p = 0.77; 9m p = 0.16; 12m p < 1 × 10−15). D, The NMDA-receptor-mediated EPSC differed among groups (nested one-way ANOVA, F(3,38) = 10.51, p = 3.6 × 10−5) and the 12m amplitudes were significantly lower than control (Dunnett’s multiple comparison: 6m p = 0.97; 9m p = 0.54; 12m p < 1 × 10−15). E, There was a weak but statistically significant correlation of Log10(EPSCAMPA) with the IOP integral (F(1,70) = 24.5, R2 = 0.26, p = 0.0000049). F, The AMPA/NMDA ratio did not significantly differ across groups (nested one-way ANOVA, F(3,38) = 1.145, p = 0.34). Group sizes: control total n = 46 cells, 16 mice (controls by age 6m n = 18 cells, 5 mice; 9m n = 23 cells, 9 mice; 12m n = 5 cells, 2 mice). G, Paired-pulse ratio differed among groups (nested one-way ANOVA, F(3,38) = 6.608, p = 0.0011) and was significantly higher in 12m D2 mice compared with controls (Dunnett’s multiple comparison: 6m p = 0.75; 9m p = 0.79; 12m p = 0.0040). C, D, F, G, Median ± IQR. Sample sizes: Control, n = 40 cells, 12 mice (controls by age: 6m n = 13 cells, 4 mice; 9m n = 22 cells, 8 mice; 12m n = 5 cells, 2 mice); 6m n = 21 cells, 7 mice; 9m n = 21 cells, 9 mice; 12m n = 29–31 cells, 10 mice. **p < 0.01; ****p < 0.00005; ns p > 0.05.