| Project/Area Number |
04670099
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
環境生理学(含体力医学･栄養生理学)
|
|---|
| Research Institution | DOKKYO UNIVERSITY SCHOOL OF MEDICINE |
|---|
Principal Investigator |
YAMAOKA Sadao DOKKYO UNIV.SCH.MED., Professor, 医学部, 教授 (50049813)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
TAKAKUBO Fumie EHIME UNIV.SCH.MED., Assistant Professor, 医学部, 助手 (60143591)
WATANABE Kazuto DOKKYO UNIV.SCH.MED., Assistant Professor, 医学部, 助手 (80146167)
KOIBUCHI Noriyuki DOKKYO UNIV.SCH.MED., Assistant Professor, 医学部, 助手 (80234681)
OHTAKE Hideki DOKKYO UNIV.SCH.MED., Associate Professor, 医学部, 助教授 (00049214)
|
|---|
| Project Period (FY) |
1992 – 1994
|
| Project Status |
Completed (Fiscal Year 1994)
|
| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1994: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1993: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1992: ¥900,000 (Direct Cost: ¥900,000)
|
|---|
| Keywords | Circadian Rhythm / Clock related Gene / CellCulture / Cloning / Suprachiasmatic Nucleus / Fos-like Protein / Differential Display Method / Differential Plaque Hybridization / 神経ペプチド / アニソマイシン / c-fos / バゾプレッシン / 免疫組織化学 |
|---|
| Research Abstract |
1). Several peptide neuron exist in the suprachiasmatic nucleus (SCN ; supposed mammalian circadian oscillator). The microinjections of anti-peptides (anti-VIP,-PHI,-SRIH) into SCN of eye-enucleated rats as passive immunization did not change tne circadian locomotor or sleep rhytym. Glutamate and NMDA showed the light pulse like phase shift response in eye-enucleated free-run rat.
2). The Fos expression in SCN was changed without light exposure, depending on circadian locomotor activity rhythm. The inactive phase showed more than the active phase in Fos expression.
3). We have developed a SCN cell culture. The SCN regions were dissected from 4-to 6-day-old rat pups and dissociated cells were cultured in a defined medium. In all the cultures, the release of vasopressin (AVP) showed clear circadian oscillation, which appeared within a few days in culture and lasted for more than a month. The peak of AVP release was observed at subjective day. Using this culture system, the effect of anisom
… More
ycin, an inhibitor of protein synthesis, on the circadian rhythm was studied. A phase-delay of more than 15h could be produced by a 6-h anisomycin pulse. These results strongly suggest that protein synthesis may be involved in the generation of circadian rhythums in mammals.
4). Circadian behavior in mammals is believed to be controlled by genes expressed in the SCN.To screen for genes that may control circadian rhythms, we have adapted the differential display method. We have detected the about 30 differentially expressed genes at two circadian times (CT10 and CT22 where CT12 is equivalent to the onset of activity) from the SCN of adult eye enucleated free-running rats. In the next step, we have screened the highly expressed 63 clones in SCN at CT10 and 43 clones at CT22 by differential plaque hybridization. Now, we are continuing the further genes screening and their subcloning. After genes cloning, we will proceed the determination of their nucleotide sequences and their physiological nature.
5). To establish the convenient model for studying the rhythm generation mechanism, we are using some mutant animals. We have recorded the circadian locomotor activity of the zitter rat that shows the vacuole formation in the brain. They indicated the early aging changes in circadian rhythm and their circadian rhythmicity gradually disrupted until seven months of age. It is expected that the study of their aging process may explain the part of generation mechanism in circadian rhythm. Less
|
