The Human Hair Follicle, A Bistable Organ?

The study conducted over 14 years with ten male volunteers, both alopecic and non-alopecic, analyzed 930 individual follicles and about 9000 hair cycles. It found that hair follicle behavior is highly variable and operates independently, suggesting a stochastic rather than a synchronized, cyclical growth pattern. The concept of the hair follicle as a bistable organ, existing in either an active or dormant state with transitions controlled by a lognormal distribution, was introduced. The term "neogen" was coined for the transition phase from telogen to anagen. The study concludes that human hair follicles fluctuate between steady states in a stochastic manner, which could impact our understanding of tissue homeostasis and epithelial-mesenchymal interactions.