Opioids depress minute ventilation primarily by reducing respiratory rate. This results from direct effects on the preBötzinger Complex as well as from depression of the Parabrachial/Kölliker-Fuse Complex, which provides excitatory drive to preBötzinger Complex neurons mediating respiratory phase-switch. Opioids also depress awake drive from the forebrain and chemodrive.
Keywords: Parabrachial Nucleus/Kölliker-Fuse Complex; awake drive; chemodrive; opioids; preBötzinger Complex.