“…B and C adapted from Mutolo et al (2007) and Cinelli et al (2014), respectively. possibly, to obtain new hints for further investigations on the basic neural mechanisms operating in the respiratory network of higher vertebrates, including mammals. The vast majority of respiratory motoneurons are located in the facial, glossopharyngeal and, especially, vagal nuclei, while the neural aggregate responsible for respiratory rhythm generation appears to be located in a region rostrolateral to the trigeminal motor nucleus (Rovainen, 1977(Rovainen, , 1979(Rovainen, , 1983(Rovainen, , 1985Thompson, 1985;Russell, 1986;Bongianni et al, 1999Bongianni et al, , 2002Bongianni et al, , 2006Guimond et al, 2003;Martel et al, 2007;Mutolo et al, 2007). Mutolo et al (2007) reported that opioids have a modulatory role in the respiratory network and, in particular, that microinjections of the -opioid receptor agonist DAMGO at sites rostrolateral to the trigeminal motor nucleus abolish the respiratory rhythm.…”