March 5, 2019
Keio University School of Medicine
A research group from the Department of Ophthalmology, Keio University School of Medicine, led by Professor Kazuo Tsubota, Project Lecturer Motoko Kawashima, and Project Assistant Professor Kokoro Sano, in collaboration with a research group from the Department of Neuropsychiatry, led by Professor Masaru Mimura and Associate Professor Kenji Tanaka, has been conducting joint research on the relationship between environmental factors and dry eye disease.
The team has now discovered that stressed mice experience a decrease in tear volume, but this stress-induced reduction is not observed in mice housed in an "enriched environment"—a large cage with toys shared by multiple mice. They also found that when mice with reduced tear volume due to stress were moved to an "enriched environment," their recovery was accelerated. Furthermore, they discovered differences in the expression levels of brain-derived neurotrophic factor (BDNF) in the brain between stressed conditions and the "enriched environment," and that tear volume decreased in a model where BDNF expression was suppressed. These results reveal that environmental factors can alter tear volume and suggest that brain BDNF may be involved in regulating tear secretion.
These research findings provide new insights, suggesting that one's environment is involved in the regulation of tear secretion via the brain. It is hoped that further development of this research will lead to proposals for creating environments that can prevent and improve dry eye disease. Additionally, this work is expected to help elucidate the relationship between dry eye disease and other BDNF-related disorders, such as stress-related illnesses.
The results of this research were published in the online edition of the interdisciplinary general journal "Scientific Reports" on March 4 (GMT).
Please see below for the full press release.