Fig. 4.

Effects of 0.5 and 5 mM DAMGO bilaterally microinjected into the caudal ventral respiratory group (cVRG) on baseline respiratory activity and cough reflex responses induced by mechanical stimulation of the tracheobronchial tree. Stimulation periods marked by filled bars. Anaesthetized, spontaneously breathing rabbits. Traces are phrenic integrated neurogram (Phr IN); phrenic neurogram (Phr N); abdominal integrated electromyographic activity (Abd IEMG); abdominal electromyographic activity (Abd EMG); tracheal pressure (TP). Anaesthetized, spontaneously breathing rabbits. Modified from Mutolo et al. 2010.