CAREER: determining how light modulates respiratory behavior to inform an increasingly light-polluted world

Light pollution poses a critical environmental challenge that affects over 23% of the Earth’s landscape and increases annually. Living creatures use Earth’s predictable, 24-hr light:dark cycle to organize and optimize biological processes. While this has been beneficial for millions of years, the modern use of artificial light at night, which includes environmental light pollution and night shiftwork, hijacks light-sensing mechanisms and disrupts biological processes. Recently, light has been found to affect one of the most shared and essential biological processes – breathing. This project will advance the understanding of how light affects fundamental biology by defining the neurobiological pathways used by light to affect breathing. Integrated into the research program, this project emphasizes the education and training of undergraduate students in creative problem-solving skills. These skills are expected to foster the next generation of STEM innovators to promote scientific discovery in an ever-changing world. Defining the neurobiological circuits that mediate light’s effects on breathing can better equip society to predict and respond to the physiological effects of light pollution. The goal of this project is to identify the retinal and brain pathways used by light to modulate breathing and blood gas homeostasis. This project uses whole-body plethysmography and a combination of chemogenic and viral approaches in transgenic mice to: 1) Determine the neuronal populations by which intrinsically-photosensitive retinal ganglion cells (ipRGCs) modulate breathing rate and minute ventilation, and 2) Determine the extent to which ipRGC projections to the hypothalamic biological clock organize the respiratory chemoreflex to the light:dark cycle. This contribution is significant because it critically expands the current understanding of breathing behavior to include light as a fundamentally important, ubiquitous, and previously undocumented modulator of breathing. Overall, this project is expected to positively impact several research fields, including basic and clinical respiratory physiology, circadian biology, neuroscience, and ecology. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.