Figure 7. Mechanisms for inspiratory network rhythmogenesis change during embryonic development.
(A) Schematic representation of an in vitro slice preparation used for electrophysiological recording of spontaneous preBötC network activity (integrated traces, Int preBötC) in control conditions (top traces) or in the presence of either FFA (50 µM, middle trace, left) or Ril (20 µM, middle trace, right) alone or in combination (bottom traces) at E16.5. (B) Bar histograms representing the percentages of cycle frequency change (mean ± SEM) compared to control under the different pharmacological conditions illustrated in A. Asterisks indicate significant differences (t-test, p<0.05); n = number of experiments in each case. (C,D) same layout as (A,B) for experiments performed at E18.5. Note that unlike at E16.5 where both FFA and Ril significantly reduced rhythmogenesis, blockade of either ICAN or INaP alone did not significantly perturb rhythm generation at E18.5. Also, blockade of both conductances at E16.5 was sufficient to completely suppress rhythm generation, but not at E18.5.