Figure 5
Slc7a10 deletion is associated with decreased spinal cord glycine levels.
Whole spinal cord lysates from P21 mice were assayed for amino acid content by ALEX-CIS GCTOF (a). Mean glycine levels are significantly decreased in Slc7a10-null mice compared to heterozygous and wild type littermates (****p < 0.0001). Mean threonine levels are significantly increased in Slc7a10-null mice compared to heterozygous and wild type littermates (**p = 0.003). No significant differences were detected among wild type and heterozygous littermates. SLC7A10 deficiency is associated with reduced motor neuron glycinergic mIPSC amplitudes. Glycinergic mIPSC traces from Slc7a10 wild type, heterozygous, and knockout mice (b). Mean glycinergic mIPSC amplitudes are significantly reduced in heterozygous and knockout mice compared to wild type (****p < 0.0001) (c,d). Mean glycinergic mIPSC frequency does not significantly differ among genotypes (p = 1.0 for wild type vs. heterozygote, p = 0.4 for wild type vs. knockout) (e,f). Normalized average waveforms of glycinergic mIPSCs from spinal cord motor neurons (g). Mean decay times do not differ among Slc7a10 genotypes (h). n ≥ 10 total cells from ≥ 3 biological replicates. GABAergic mIPSC amplitude and frequency is significantly increased in Slc7a10-null spinal cord motor neurons. Mean GABA-mediated mIPSC amplitudes were significantly increased in Slc7a10-null motor neurons (i,j) (amplitude, in pA, 31.9 ± 1.6 vs. 26.2 ± 1.1, knockout vs. wild type, **p = 0.008). Mean GABA-mediated mIPSC frequencies were also significantly increased (k) (frequency, in Hz, 6.9 ± 0.8 vs. 4.3 ± 0.5, knockout vs. wild type, *p = 0.01). n = 11 total cells from 3 biological replicates. NMDAR- and AMPAR-mediated glutamatergic transmission is significantly diminished in Slc7a10-null spinal cord motor neurons. Excitatory currents in Slc7a10 wild type and knockout mice (l). Glutamatergic currents are diminished in Slc7a10-null mice compared to wild type (m, amplitude, in pA, 29.4 ± 1.1 vs. 38.8 ± 3.0, knockout vs. wild type, *p = 0.01; n, frequency, in Hz, 8.3 ± 1.0 vs. 20.7 ± 3.9, knockout vs. wild type, *p = 0.01). n = 11 total cells from 3 biological replicates. Error bars indicate mean ± SEM.
