Skip to main content
. 2019 Dec 16;8:e50613. doi: 10.7554/eLife.50613

Figure 1. µOR activation depresses inspiratory frequency without affecting burstlet fraction.

Figure 1.

(A) Representative traces of ∫preBötC and ∫XII population activity in 9/1.5 ACSF control and 30 nM DAMGO. Scale bar, 10 s. (B) Representative time course of an experiment where increasing concentrations of DAMGO were bath-applied in 9/1.5 ACSF. Interevent intervals (int.) in preBötC (top) and XII (bottom) are plotted. In this experiment, 100 nM DAMGO led to cessation of rhythm. (C) Average burstlet fraction and preBötC f in 9/1.5 ACSF and 10 nM and 30 nM DAMGO. Increasing concentrations of DAMGO did not significantly affect burstlet fraction whereas preBötC f was significantly lower in 10 nM and 30 nM DAMGO. *, p<0.05, One-way ANOVA, post-hoc Tukey test, n = 6. (D) Representative traces of ∫preBötC and ∫XII population activity in 9/1.5 ACSF control and in 30 nM DAMGO with 100 µM picrotoxin and 1 µM strychnine (picrotoxin/strychnine). Scale bar, 10 s. (E) Average preBötC burst and XII burst amplitude (amp.) in 9/1.5 ACSF and in 30 nM DAMGO with 100 µM picrotoxin and 1 µM strychnine (picrotoxin/strychnine). Addition of DAMGO and picrotoxin/strychnine increased preBötC burst amplitude compared to 9/1.5 ACSF control while XII burst amplitudes were not significantly different. The low frequency or lack of preBötC burstlets precluded analysis of their amplitudes. *, p<0.05, Student’s t-test, n = 13. (F) Average burstlet fraction and preBötC f in 9/1.5 ACSF and in 30 nM DAMGO with 100 µM picrotoxin and 1 µM strychnine (picrotoxin/strychnine). When picrotoxin/strychnine was added with DAMGO, preBötC f remained significantly reduced and burstlet fraction was similar. *, p<0.05, Student’s t-test, n = 13. (G) Representative traces of ∫preBötC and ∫XII population activity in 3/1 ACSF control and 30 nM DAMGO. Both small amplitude burstlets (•), which did not produce XII activity, and large amplitude bursts, which generated XII bursts, were observed. Scale bar, 10 s. (H) Representative time course of an experiment, where increasing concentrations of DAMGO were bath-applied in 3/1 ACSF. Interevent intervals in preBötC (top) and XII (bottom) are plotted. In this experiment, 100 nM DAMGO led to cessation of XII activity while preBötC rhythm persisted. (I) Average burstlet fraction and f in 3/1 ACSF and 10 nM and 30 nM DAMGO. Increasing concentrations of DAMGO did not significantly affect burstlet fraction whereas preBötC f was significantly lower in 30 nM DAMGO. *, p<0.05, One-way ANOVA, post-hoc Tukey test, n = 7.