61 citations
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June 2018 in “Proceedings of the National Academy of Sciences of the United States of America” This study found that light stimulation of intrinsically photosensitive retinal ganglion cells in the eyes can activate hair follicle stem cells through a neural circuit involving the sympathetic nervous system.
April 2018 in “Journal of Investigative Dermatology” This study found that external light can rapidly activate hair follicle stem cells in animals via a retinal light-sensing pathway linked to the central and autonomic nervous systems.
127 citations
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December 2005 in “Experimental Dermatology” This study provides evidence that psychoemotional stress inhibits hair growth in mice by affecting the brain-hair follicle axis, with specific neuropeptides and treatments modulating this effect.
March 2025 in “Molecular Medicine” This study on C57BL/6 mice found that subcutaneous cholesterol injections significantly promoted hair regeneration by enhancing hair follicle stem cell proliferation, highlighting the role of the PKA-tyrosine hydroxylase-sympathetic nervous system pathway in this process.
260 citations
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January 2020 in “Nature” Stress can cause hair to turn gray by depleting stem cells.