<prompt> Pacemaker regulating the rate of respiration ?Pneumotaxic centreDorsal group of nucleusApneustic centrePre-Botzinger Complex  <response>: Ans. is d i.e., Pre-Botzinger Complex The main components of the respiratory control pattern generator responsible for automatic respiration are located in the medulla. Rhythmic respiration is initiated by a small group of synaptically coupled pacemaker cells in the pre-Botzinger complex on either side of the medulla between the nucleus ambiguus and the lateral reticular nucleus. 