Figure 7.
Burstlet/burst/doublet rhythms elicited in vivo. A, Respiratory pattern is shown in anesthetized and vagotomized adult rat before and after bicuculline injection into preBötC and BötC and bombesin injection into preBötC only. A, Left, Airflow and integrated DIAEMG activity. After local injection of bicuculline and bombesin, small bursts (indicated by green asterisk) appeared between inspiratory bursts that resemble leak through of burstlets seen in vitro (Fig. 4B). Doublets, e.g., gray box, were also observed. A, Right, Average integrated DIAEMG during burstlets (green) and bursts (maroon). B, Left, After vagotomy and injection of bicuculline and strychnine into preBötC, doublet bursts appeared. Gray boxes indicate doublets. B, Right, Average integrated waveforms of DIAEMG from 20 bursts (maroon) and doublets (black) after vagotomy and injection of inhibitory antagonists. While doublet peaks were not significantly different, the second peak in the average doublet waveform appears smaller due to alignment of doublets by their onset and differences in the doublet intrapeak interval.