Project Summary/Abstract Despite recent advances with new therapies, a huge proportion of migraine patients are still unable to use established therapeutics. For many patients, treatments are not effective, even newly approved CGRP mAbs have response rates of only ~50%. For others they are unsafe due to contraindications (triptans), or like opioids, not suited for long term use, even exacerbating existing migraine headache. This illustrates that there are still major gaps in our understanding of migraine mechanisms. It is therefore imperative that we investigate the underlying molecular mechanisms involved, geared towards identifying novel therapeutic targets with potential for rapid translation to the clinic. Recent data have identified the adenosine A3 receptor (A3AR) as a novel target for pain. Our recent work has also established that production of the highly noxious reactive nitroxidative species, peroxynitrite (PN), causes downstream modifications to glutamatergic signaling and NLRP3/IL-1β-driven neuroinflammation, to mediate nociceptive spinal sensitization. We show that A3AR agonists attenuate these nociceptive mechanisms in diverse rodent models of neuropathic pain, providing persistent pain relief. Despite this, little is known about A3AR-PN mechanisms in trigeminovascular migraine models. However, our preliminary data demonstrate that A3AR are expressed in important peripheral and central regions along the migraine pain pathway, and A3AR agonists inhibit migraine-like responses in several rodent models of migraine that are highly predictive of therapeutic efficacy. Additional data also implicate both PN and NLRP3 production in mediating migraine-like nociceptive responses. This is exciting as A3AR agonists are already in clinical trials in non-pain disorders, have a good safety profile, and appear well suited for chronic pain management. Based on these observations we hypothesize that PN production and activation of its downstream nociceptive signaling ca