Jim Kuchenbecker and Jay Neitz are part of a collaborative team that has been awarded a highly competitive, nearly $8 million grant provided by the National Institute of Neurological Disorders and Stroke (NINDS). The grant will fund groundbreaking research titled: “Neural Mechanisms of Colored Light-Driven Analgesia.” The group’s research explores the use of colored light to modulate pain pathways in the brain. This work represents an innovative approach to managing pain without the use of opioids, contributing to a vital area of research aimed at addressing the ongoing opioid crisis. The project is set to span five years. It will involve a multidisciplinary team of investigators, including Jay Neitz, PhD, vision neuroscientist, and Jim Kuchenbecker, PhD, bioengineer, and vision scientist at the University of Washington and two other institutions, Norman Taylor, MD, PhD at the University of Utah and Matt Mauck at the University of North Carolina. This grant, a part of the NIH HEAL Initiative, supports collaborative approaches to generate new mechanistic knowledge to improve pain management.
In clinical studies, colored light has been shown to be more effective in ameliorating pain than white light when compared at equal brightness. This implicates color-opponent circuitry in the primate retina in the neural mechanism of light-driven analgesia. Because of the unique mechanisms responsible for carrying color information in humans shared only by other primates, nonhuman primate research has been essential color research. During the last century, it was assumed that the neurons in the retina carrying color information were involved in conscious color perception, mediating the sensations of red, green, blue, and yellow. However, in 2005, Dennis Dacey and colleagues at the University of Washington discovered that retinal ganglion cells involved in non-image-forming visual capacities, including synchronizing our internal biological clock to the external day, are color-opponent making them sunrise-sunset detectors sensitive to the change in the color of the sky from blue to orange when the sun is at the horizon.
Since then, Kuchenbecher, Neitz, and their colleagues in the UW Department of Ophthalmology have discovered that multiple types of neurons in the primate retina carry color information integrating environmental light cues and relaying them to various brain centers. Their influence extends far beyond circadian entrainment, encompassing sleep, mood, cognition, metabolism, and overall health. Understanding these diverse roles has significant implications for therapies targeting light exposure to improve health and well-being. These include influencing pain perception and sensitivity. This may make sense in terms of primate evolution when being able to endure pain may have been critical to survival. After the sun goes down, an injured primate ancestor exposed to the elements in the great outdoors is subject to many life-threatening hazards, including hypothermia, starvation, or being killed by predators. Seeing the color of the sunset might indicate to an injured primate ancestor that getting back to safety is more important than focusing on the pain they are experiencing. Signals from color-sensitive ganglion cells may communicate with ascending pain centers to ameliorate pain until the animal is safe at home. The proposed research will illuminate the underlying mechanisms and has the promise to provide new strategies for controlling pain using light.