Administrative Supplement Proposal: Abstract R00 AT009466: Affective Sensory Pathways of Light Stroking and Deep Pressure Touch Dr. Case is as an Assistant Professor in the Department of Anesthesiology at the University of California San Diego (UC San Diego). After overcoming covid-related delays, her R00 study on mechanisms of affective touch is running smoothly and on track with her current SARP. The proposed administrative supplement is requested to add two highly innovative aims to increase the impact of the originally proposed study in establishing novel mechanisms of action for sensory-based complementary approaches such as massage therapy. The existing R00 study seeks to identify factors underlying blunted affective touch perception in individuals with chronic pain, and to compare the pain-relieving mechanisms and effects of light gentle stroking and deep pressure between patients with Fibromyalgia (FM) and healthy controls. The current administrative proposal adds two aims: 5) Determine the local effect of subcutaneous OT on experimental pain and 6) Determine the local effect of subcutaneous OT on touch pleasantness. Recent research in rodents demonstrates that oxytocin strongly modulates C-fibers in the spinal cord and at the terminal axon. In humans, systemic oxytocin modulates affective touch perception, and skin injection reduces postsurgical pain. However, peripheral effects of oxytocin on affective touch perception have never been tested in humans. Study results are expected to significantly impact fundamental understanding of the mechanisms of peripheral pathways for touch pleasantness and pain reduction. We expect this project to lead to a competitive R01 submission to test whether local effects of oxytocin differ in patients with chronic pain, who exhibit C-nociceptor sensitization and reduced touch pleasantness. This contribution will inform subsequent research on mechanisms of manual touch therapies and provide a new direction to test differences in individuals with chronic pain.