Figure 3. Network-level effects of MOR activation on spiking activity in the preBötC in vitro and in vivo.
(A) Representative ʃpreBötC activity from a horizontal slice during increasing concentrations of DAMGO. Orange asterisks indicate burst failures. (B) Averaged inter-burst intervals at baseline and in DAMGO demonstrating changes in IBI spiking. (C) Quantified ʃIBI spiking (RM one-way ANOVA [p<0.0001] with Bonferroni post hoc tests), burst frequency (RM one-way ANOVA [p<0.0001] with Bonferroni post hoc tests), frequency irregularity (RM mixed-effects analysis [p=0.01] with Dunnett’s post hoc tests), and amplitude irregularity (RM mixed-effects analysis [p=0.16] with Dunnett’s post hoc tests) from n=30 slices. (D) Averaged successful bursts compared to burst failures (top) and example intracellular recording during a failed burst (bottom). (E) Quantified fraction of burst failures during increasing concentrations of DAMGO (RM mixed-effects analysis [p<0.0001] with Bonferroni post hoc tests). (F) Schematic of in vivo experimental preparation with example simultaneous ʃXII and ʃpreBötC recordings. (G) Representative ʃXII and ʃpreBötC activity at baseline and following i.p. morphine. (H) Averaged ʃIBI spiking at baseline and following morphine. (I) Quantified ʃIBI spiking, breathing frequency, inter-burst interval, and inspiratory time (TI) (n=6; ratio paired t-tests). (J) Example changes in preBötC burst morphology in response to morphine administration in vivo. Data presented as means ± SE; significance of post hoc tests: *p<0.05, #p<0.01, †p<0.001, ‡p<0.0001 compared to baseline.