Modeling the Dynamics of Human Hair Cycles by a Follicular Automaton
The hair follicle successively goes through the anagen, catagen, telogen, and latency phases, which correspond, respectively, to hair growth, arrest, shedding, and absence before a new anagen phase is initiated. Experimental observations collected over a period of 14 years in a group of 10 male volu...
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Published in | Proceedings of the National Academy of Sciences - PNAS Vol. 97; no. 15; pp. 8328 - 8333 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
United States
National Academy of Sciences of the United States of America
18.07.2000
National Acad Sciences National Academy of Sciences The National Academy of Sciences |
Subjects | |
Online Access | Get full text |
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Summary: | The hair follicle successively goes through the anagen, catagen, telogen, and latency phases, which correspond, respectively, to hair growth, arrest, shedding, and absence before a new anagen phase is initiated. Experimental observations collected over a period of 14 years in a group of 10 male volunteers, alopecic and nonalopecic, allowed us to determine the characteristics of scalp hair follicle cycles. On the basis of these observations, we propose a follicular automaton model to simulate the dynamics of human hair cycles. The automaton model is defined by a set of rules that govern the stochastic transitions of each follicle between the successive states anagen, telogen, and latency, and the subsequent return to anagen. The transitions occur independently for each follicle, after time intervals given stochastically by a distribution characterized by a mean and a variance. The follicular automaton model accounts both for the dynamical transitions observed in a single follicle and for the behavior of an ensemble of independently cycling follicles. Thus, the model successfully reproduces the evolution of the fractions of follicle populations in each of the three phases, which fluctuate around steady-state or slowly drifting values. We apply the follicular automaton model to the study of spatial patterns of follicular growth that result from a spatially heterogeneous distribution of parameters such as the mean duration of anagen phase. When considering that follicles die or miniaturize after going through a critical number of successive cycles, the model can reproduce the evolution to hair patterns similar to well known types of diffuse or androgenetic alopecia. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 Communicated by I. Prigogine, Free University of Brussels, Brussels, Belgium To whom reprint requests should be addressed. E-mail: agoldbet@ulb.ac.be. |
ISSN: | 0027-8424 1091-6490 |
DOI: | 10.1073/pnas.97.15.8328 |