Figure 9:

Pooled data for the changes (delta) in inputs to (A) the inspiratory off-switch (derived from the inspiratory duration) and (B) inspiratory on-switch (derived from the expiratory duration) with naloxone injections into the Caudal Medullary Raphe (raphe) or the respiratory rhythm generator, i.e., the Parabrachial Nucleus/Kölliker Fuse Complex (PBN/KF) plus preBötzinger Complex (preBötC). Deltas are compared between naloxone injections without remifentanil infusion (data from section 3.4., white boxes) or at “analgesic” (section 3.1.) or “apneic” systemic remifentanil concentrations (section 3.2.). Deltas from different cohorts (naloxone injection orders) were pooled for matching injections (same location and remifentanil concentration) when they were not statistically different. Comparison of inputs to inspiratory off- and on-switch showed no difference between naloxone injections at different remifentanil concentrations (black bracket). C: Statistical comparisons between deltas from different cohorts for matching injections (see above) mostly showed no significant differences, and data were thus pooled and used for the analyses in A and B. Inputs to inspiratory on-switch during “apneic” remifentanil concentrations increased more with naloxone injection into the PBN/KF+preBötC after prior naloxone injection into the raphe and are displayed separately (B, blue bracket, p<0.001). *: Mann-Whitney-U test for two comparisons, ^: Kruskal-Wallis test for three comparisons.