Opioids depress breathing through two small brainstem sites

The rates of opioid overdose in the United States quadrupled between 1999 and 2017, reaching a staggering 130 deaths per day. This health epidemic demands innovative solutions that require uncovering the key brain areas and cell types mediating the cause of overdose--opioid respiratory depression. Here, we identify two primary changes to breathing after administering opioids. These changes implicate the brainstems breathing circuitry which we confirm by locally eliminating the -Opiate receptor. We find the critical brain site is the origin of the breathing rhythm, the preBotzinger Complex, and use genetic tools to reveal that just 70-140 neurons in this region are responsible for its sensitivity to opioids. Future characterization of these neurons may lead to novel therapies that prevent respiratory depression while sparing analgesia.