1999 Fiscal Year Final Research Report Summary
Studies on the ontogeny of the biological clock in the human fetus
| Project/Area Number |
09470361
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Obstetrics and gynecology
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| Research Institution | KYUSHU UNIVERSITY |
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Principal Investigator |
NAKANO Hitoo Department of Obstetrics and Gynecology, Graduate School of Medical Sciences, Kyushu University, Professor, 大学院・医学系研究科, 教授 (40038766)
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| Co-Investigator(Kenkyū-buntansha) |
TSUKIMORI Kiyomi Maternity and Perinatal Care Unit, Kyushu University Hospital, Assistant Professor, 医学部, 講師 (90253450)
SATO Shoji Maternity and Perinatal Care Unit, Kyushu University Hospital, Assistant Professor, 医学部, 講師 (00225947)
KOYANAGI Takashi Department of Human Development, Graduate School of Medical Sciences, Kyushu University, Professor, 大学院・医学系研究科, 教授 (30136452)
HORIMOTO Naoki Department of Human Development, Graduate School of Medical Sciences, Kyushu University, Research Associate, 大学院・医学系研究科, 助手 (40243927)
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| Project Period (FY) |
1997 – 1999
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| Keywords | human fetus / biological clock / eye movement / ultradian rhythm / circadian rhythm / ontogeny / REM / NREM sleep |
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| Research Abstract |
The aim of this research project is to elucidate the developmental process of ultradian and circadian rhythms in the human fetus in utero, from the view point of the ontogeny of the biological clock.
It was evident that : (1) The controlling center of ultradian rhythm (seen in eye movement / no eye movement period alternation or FHR variation), lying in the ponto-medullar region, starts to function at around 30 weeks' gestation and reaches maturation at term. (2) With regard to the sleep and waking states in the human fetus, both slow eye movement coexisting with rapid eye movement at 33 weeks' gestation onwards, and penile tumescence relating to the eye movement period as well, suggest that the generating center of REM sleep in the pons is functioning. (3) At 35 weeks' gestation onwards, regular mouthing movement concurrent with the no eye movement period indicates that this period is comparable to NREM sleep, thereby suggesting that the neural center, responsible for NREM sleep, from the pons through the thalamocortical pathway to the cerebral hemisphere may begin to function at around 35 weeks' gestation. (4) The temporal relationship between the onset of the eye movement period and micturition at term may be interpreted by the anatomical proximity of the controlling parts of both phenomena in the pons, and their interaction during the course of development. (5) Two different conditions emerge from fetal stomach movement, at the latest at 27 weeks' gestation, and begin manifesting from 29 weeks' onwards. The chronological changes in these conditions cluster into 'active' and 'quiet' phases from 31 weeks' gestation onwards. (6) Using maximum entropy power spectral analysis, the eye movement pattern at term was revealed to have a 16-29 hour periodicity.
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