PROJECT SUMMARY
Chronic pain affects nearly 1 in every 5 adults worldwide 1, posing a major public health concern and economic
burden. Yet, despite the widespread prevalence of chronic pain, few effective strategies for long-term pain
management exist. Historically, physicians have relied upon a cocktail of analgesics, including tricyclic
antidepressants, serotonin norepinephrine reuptake inhibitors, and opiates, to treat persistent symptoms in
chronic pain patients 54. However, this approach carries significant risks – reliance upon prescription opioids
has fueled the opioid abuse epidemic that has crippled the United States for the past two decades, and long-
term use of opioids has conversely been shown to increase pain sensitivity over time, necessitating larger and
larger doses to achieve analgesic efficacy 53. Therefore, to successfully combat the opioid epidemic, we must
investigate underlying mechanisms of pain chronification in pursuit of novel, non-addictive pain interventions.
Until recently, much of the pain field has focused on peripheral nervous system and spinal cord circuit
dysfunction, which primarily influence the somatosensory elements of chronic pain. Chronic pain, however, is
more than purely a sensory phenomenon; patients also suffer from the “unpleasantness” or negative valence
associated with pain 22. Recent work from our collaborators has identified a specific ensemble of neurons within
the basolateral amygdala (BLA) that encodes for the negative valence of pain 22. However, it remains unknown
how activity within these nociceptive BLA neurons and the circuits in which they are embedded are altered
post-injury, and whether these changes contribute to pain chronification. Using an innovative activity-based
rabies screen pioneered by our lab 28 in parallel with an unbiased whole-brain c-Fos activity mapping approach,
we can generate a list of input regions to the BLA whose activity is elevated exclusively during chronic pain. To
test the functional contribution of these input circuits in pain chronification, we will perform chemogenetic
inhibition studies in tandem with classical pain assays. By identifying brain-wide, circuit-level changes that
occur post-injury to promote chronic pain, we will elucidate key brain regions and circuit targets that will enable
the development of non-opiate therapies for mitigating chronic pain.