The mammals can not only entrain to the natural 24-h light–dark cycle, but also to the artificial cycle with non 24-h period through the main clock named suprachiasmatic nucleus in the brain. The range of the periods...The mammals can not only entrain to the natural 24-h light–dark cycle, but also to the artificial cycle with non 24-h period through the main clock named suprachiasmatic nucleus in the brain. The range of the periods of the artificial cycles which the suprachiasmatic nucleus(SCN) can entrain, is called entrainment range reflecting the flexibility of the SCN. The SCN can be divided into two groups of neurons functionally, based on the different sensitivities to the light information. In the present study, we examined whether the entrainment range is affected by this difference in the sensitivity by a Poincaré model. We found that the relationship of the entrainment range to the difference depends on the coupling between two groups. When the coupling strength is much smaller than the light intensity, the relationship is parabolic-like, and the maximum of the entrainment range is obtained with no difference of the sensitivity. When the coupling strength is much larger than the light intensity, the relationship is monotonically changed, and the maximum of the entrainment range is obtained when the difference is the largest. Our finding may provide an explanation for the exitance of the difference in the sensitivity to light-information as well as shed light on how to increase the flexibility of the SCN represented by widening the entrainment range.展开更多
基金National Natural Science Foundation of China(Grant Nos.11875042 and 11505114)the Innovation Foundation of Shanghai Aerospace Science and Technology,China(Grant No.SAST2018-22)the Course of Scientific Research Project of Shanghai University for Science and Technology(Grant No.13002100).
文摘The mammals can not only entrain to the natural 24-h light–dark cycle, but also to the artificial cycle with non 24-h period through the main clock named suprachiasmatic nucleus in the brain. The range of the periods of the artificial cycles which the suprachiasmatic nucleus(SCN) can entrain, is called entrainment range reflecting the flexibility of the SCN. The SCN can be divided into two groups of neurons functionally, based on the different sensitivities to the light information. In the present study, we examined whether the entrainment range is affected by this difference in the sensitivity by a Poincaré model. We found that the relationship of the entrainment range to the difference depends on the coupling between two groups. When the coupling strength is much smaller than the light intensity, the relationship is parabolic-like, and the maximum of the entrainment range is obtained with no difference of the sensitivity. When the coupling strength is much larger than the light intensity, the relationship is monotonically changed, and the maximum of the entrainment range is obtained when the difference is the largest. Our finding may provide an explanation for the exitance of the difference in the sensitivity to light-information as well as shed light on how to increase the flexibility of the SCN represented by widening the entrainment range.
