Philadelphia University + Thomas Jefferson University

Brainard, George C

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George C. Brainard, PhD

Contact Dr. Brainard

900 Walnut Street
JHN 4th Floor
Philadelphia, PA 19107

(215) 503-4358 fax

Research and Clinical Interests

Photobiological regulation of the circadian and neuroendocrine systems

Jefferson's Light Research Program was founded in 1984. We study human neuroendocrine, circadian, and neurobehavioral responses to light using techniques of photobiology, radioimmunoassay, radioenzyme assay, as well as standardized psychophysical and psychiatric tests. Our development of an analytical action spectrum for the regulation of pineal melatonin by light wavelength, led in part, to the recent discovery of a novel class of photoreceptors in the eye that are responsible for the neurobehavioral effects of light in humans. The action spectrum showed that the human circadian system is most strongly regulated by blue wavelengths. Currently, our research is both basic and applied. Our basic studies on healthy humans are intended to elucidate the fundamental elements for circadian phototransduction in the eye. Our applied studies translate that basic science into both nonclinical and clinical applications. A significant concentration of our research is supported by the National Space Biomedical Research Institute, a division of NASA. Many astronauts experience sleep and circadian disruption during space flight that can lead to serious decrements in alertness and performance. This risk factor can threaten the safety of individual astronauts as well as entire missions. Our laboratory is testing nonpharmacological lighting countermeasures for these problems. If successful, these lighting countermeasures will be employed in orbiting spacecraft as well as habitats being developed for the Lunar and Mars missions. Shiftworkers here on earth also experience sleep and circadian problems and may ultimately benefit from the lighting countermeasures being developed for space exploration. In terms of clinical applications, we are studying how to improve light therapy for patients with Seasonal Affective Disorder (SAD) or winter depression. We are also testing whether or not light exposure during the nighttime is a risk factor for the development of breast and other types of cancers.


Most Recent Peer-Reviewed Publications

  1. The development of lighting countermeasures for sleep disruption and circadian misalignment during spaceflight
  2. Effects of daytime exposure to light from blue-enriched light-emitting diodes on the nighttime melatonin amplitude and circadian regulation of rodent metabolism and physiology
  3. Daytime Blue Light Enhances the Nighttime Circadian Melatonin Inhibition of Human Prostate Cancer Growth
  4. Short-wavelength enrichment of polychromatic light enhances human melatonin suppression potency
  5. The influence of red light exposure at night on circadian metabolism and physiology in Sprague-Dawley rats
  6. Diurnal spectral sensitivity of the acute alerting effects of light
  7. Exploring the power of light: From photons to human health
  8. Breast cancer and circadian disruption from electric lighting in the modern world
  9. Regulation of L1 expression and retrotransposition by melatonin and its receptor: Implications for cancer risk associated with light exposure at night
  10. Effect of different spectral transmittances through tinted animal cages on circadian metabolism and physiology in sprague-dawley rats
  11. Measuring and using light in the melanopsin age
  12. Psychosocial benefits of a novel mindfulness intervention versus standard support in distressed women with breast cancer
  13. Insulin and IGF1 enhance IL-17-induced chemokine expression through a GSK3B-dependent mechanism: A new target for melatonin's anti-inflammatory action
  14. Effect of spectral transmittance through red-tinted rodent cages on circadian metabolism and physiology in nude rats
  15. Adverse health effects of nighttime lighting: Comments on american medical association policy statement
  16. Melanopsin, photosensitive ganglion cells, and seasonal affective disorder
  17. Effects of spectral transmittance through standard laboratory cages on circadian metabolism and physiology in nude rats
  18. Human phase response curve to a single 6.5 h pulse of short-wavelength light
  19. Solid-state lighting for the International Space Station: Tests of visual performance and melatonin regulation
  20. Seasonal Affective Disorder