Figure 5.

Effect of ablation of Phox2b-expressing neurons on hypercapnic ventilatory responses. A, Schematic diagrams illustrating a delivery of Cre-dependent Casp3 into the NTS. B, Quantitative analysis of Phox2b mRNA to validate selective ablation of Phox2b-expressing neurons using qPCR. n = 9 samples from 3 mice for mCherry; n = 12 samples from 4 mice for Casp3. **p < 0.01 (Mann–Whitney test). C–E, Ablation of Phox2b-expressing neurons blunted the hypercapnic ventilatory response. Exposure to higher concentrations of CO₂ increased MV mainly via an increase in TV. However, MV was significantly reduced in Casp3-injected mice compared with mCherry-injected mice. n = 10 for each group. Two-way repeated-measures ANOVA with Bonferroni's multiple-comparisons test: *p < 0.05; **p < 0.01; ***p < 0.001; ****p < 0.0001.