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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Quantitative Study of Dual Circadian Oscillator Models under Different Skeleton Photoperiods

Full text
Author(s):
Flores, Danilo E. F. L. [1] ; Oda, Gisele A. [1]
Total Authors: 2
Affiliation:
[1] Univ Sao Paulo, Inst Biociencias, Sao Paulo - Brazil
Total Affiliations: 1
Document type: Journal article
Source: JOURNAL OF BIOLOGICAL RHYTHMS; v. 35, n. 3 FEB 2020.
Web of Science Citations: 2
Abstract

The daily proportion of light and dark hours (photoperiod) changes annually and plays an important role in the synchronization of seasonal biological phenomena, such as reproduction, hibernation, and migration. In mammals, the first step of photoperiod transduction occurs in the suprachiasmatic nuclei (SCN), the circadian pacemaker that also coordinates 24-h activity rhythms. Thus, in parallel with its role in annual synchronization, photoperiod variation acutely shapes day/night activity patterns, which vary throughout the year. Systematic studies of this behavioral modulation help understand the mechanisms behind its transduction at the SCN level. To explain how entrainment mechanisms could account for daily activity patterns under different photoperiods, Colin Pittendrigh and Serge Daan proposed a conceptual model in which the pacemaker would be composed of 2 coupled, evening (E) and morning (M), oscillators. Although the E-M model has existed for more than 40 years now, its physiological bases are still not fully resolved, and it has not been tested quantitatively under different photoperiods. To better explore the implications of the E-M model, we performed computer simulations of 2 coupled limit-cycle oscillators. Four model configurations were exposed to systematic variation of skeleton photoperiods, and the resulting daily activity patterns were assessed. The criterion for evaluating different model configurations was the successful reproduction of 2 key behavioral phenomena observed experimentally: activity psi-jumps and photoperiod-induced changes in activity phase duration. We compared configurations with either separate light inputs to E and M or the same light inputs to both oscillators. The former replicated experimental results closely, indicating that the configuration with separate E and M light inputs is the mechanism that best reproduces the effects of different skeleton photoperiods on day/night activity patterns. We hope this model can contribute to the search for E and M and their light input organization in the SCN. (AU)

FAPESP's process: 19/04451-3 - Role of the glucocorticoid-induced leucine zipper transcription factor TSC22D3 in the molecular circadian clock
Grantee:Danilo Eugênio de França Laurindo Flôres
Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
FAPESP's process: 17/16242-4 - Computational studies on photoperiodism in light and food synchronization of multi-oscillatory circadian systems
Grantee:Danilo Eugênio de França Laurindo Flôres
Support Opportunities: Scholarships in Brazil - Post-Doctoral
FAPESP's process: 17/19680-2 - Photoperiodism in South American subterranean rodents under field and laboratory conditions
Grantee:Gisele Akemi Oda
Support Opportunities: Regular Research Grants