MODEL1006230014
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created:
  W3 CDTF: Fri Jun 25 13:24:53 BST 2010
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notes: This a model from the article: The follicular automaton model: effect of stochasticity and of synchronization of hair cycles. Halloy J, Bernard BA, Loussouarn G, Goldbeter A. J Theor Biol 2002 Feb 7;214(3):469-79 11846603 , Abstract: Human scalp hair consists of a set of about 10(5)follicles which progress independently through developmental cycles. Each hair follicle successively goes through the anagen (A), catagen (C), telogen (T) and latency (L) phases that correspond, respectively, to growth, arrest and hair shedding before a new anagen phase is initiated. Long-term experimental observations in a group of ten male, alopecic and non-alopecic volunteers allowed determination of the characteristics of hair follicle cycles. On the basis of these observations, we previously proposed a follicular automaton model to simulate the dynamics of human hair cycles and the development of different patterns of alopecia [Halloy et al. (2000) Proc. Natl Acad. Sci. U.S.A.97, 8328-8333]. The automaton model is defined by a set of rules that govern the stochastic transitions of each follicle between the successive states A, T, L and the subsequent return to A. These transitions occur independently for each follicle, after time intervals given stochastically by a distribution characterized by a mean and a standard deviation. The follicular automaton model was shown to account both for the dynamical transitions observed in a single follicle, and for the behaviour of an ensemble of independently cycling follicles. Here, we extend these results and investigate additional properties of the model. We present a deterministic version of the follicular automaton. We show that numerical simulations of the stochastic version of the automaton yield steady-state level of follicles in the different phases which approach the levels predicted by the deterministic equations as the number of follicles progressively increases. Only the stochastic version can successfully reproduce the fluctuations o…
is described by: http://identifiers.org/pubmed/11846603
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modified:
  W3 CDTF: Fri Jun 25 13:24:53 BST 2010
creator:
  ORG:
    orgname: University of Auckland
  n:
    given: Catherine
    family: Lloyd
modified:
  W3 CDTF: Fri Jun 25 13:24:53 BST 2010
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volume units: 950046
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parameter: 092831
creator:
  ORG:
    orgname: University of Auckland
  n:
    given: Catherine
    family: Lloyd
parameter: 092826
parameter: 092824
creator:
  ORG:
    orgname: University of Auckland
  n:
    given: Catherine
    family: Lloyd
parameter: 092833
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modified:
  W3 CDTF: Fri Jun 25 13:24:53 BST 2010
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