Respiratory Responses to Acidosis

Data were analyzed with GraphPad (GraphPad Prism9, San Diego, California, United-States). Normality of data distribution for fR, VT and VE, for cells immunolabelled c-FOS, 5-HT, c-FOS/5-HT, PHOX2B, c-FOS/PHOX2B, for concentrations of 5-HT, 5-HTP and 5-HIAA, and for 5-HT/5-HTP and 5-HIAA/5-HT ratios were assessed using the d’Agostino and Pearson omnibus normality test. Depending on whether the distribution was normal or not, data were expressed as mean ± standard deviation or median and interquartile range [Q1; Q3] and parametric or non-parametric tests were performed: within a group of preparation, in paired conditions, paired t-test, Wilcoxon signed rank test, one-way analysis of variance, or Friedman test followed by Dunn’s or Benjamini, Krieger and Yekutieli’s multiple comparison test; between two groups, in unpaired conditions, unpaired t test, Mann & Whitney test and two-way analysis of variance followed by Benjamini, Krieger and Yekutieli’s multiple comparison test in unpaired conditions; between more than two groups, one way analysis of variance or Friedman test followed by Benjamini, Krieger and Yekutieli’s multiple comparison test. Percentages of Phox2b mutant mice acidosis-responder or acidosis-non-responder with or without etonogestrel were compared by Fisher’s exact test. Differences were considered to significant if p < 0.05.