| Project/Area Number |
06454028
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
動物生理・代謝
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| Research Institution | KYUSHU UNIVERSITY |
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Principal Investigator |
TOH Yoshihiro Kyushu University., Science., Professor, 理学部, 教授 (60037265)
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| Co-Investigator(Kenkyū-buntansha) |
MIZUTANI Akiko Kyushu University., Science., Assistant, 理学部, 助手 (80231611)
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| Project Period (FY) |
1994 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥7,500,000 (Direct Cost: ¥7,500,000)
Fiscal Year 1995: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 1994: ¥6,400,000 (Direct Cost: ¥6,400,000)
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| Keywords | mechanoreception / sensillum / chordotonal sensillum / campaniform sensillum / stretch receptor / sensory cilium / rapid freezing techniques / insect |
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| Research Abstract |
It is widely known that there are three types of mechanoreceptors in insects, which structurally and morphologically differ from each other. In the present study morphological basis of mechano-electric transduction has been examined in the three types of insect mechanoreceptors by means of rapid freezing techniques for electron microscopy.
1) The structure of the chordotonal organ was examined in cockroach antennae, Drosophila halteres, and locust femurs. Their sensory cilia show some similarity to motile cilia, being thin and long and possessing axoneme with dyenin arms. Morphological comparison between mechanically stimulated cilia and un-stimulated ones suggests that active stroke or passive waving of the sensory cilia may be involved in the mechano-electric transduction.
2) The structure of the campaniform sensillum was examined in cockroach antennae and Drosophila halteres. Their sensory cilia are characterized by the tubular body in the distal tip, which is known as a bundle of microtubules. The observation of rapid frozen specimens revealed that actin filaments occur among microtubules in the tubular body. Regular arrangement of the two types of filaments may comprise morphological basis of mechano-electric transduction in the campaniform sensilla. Depolymerization of such cytoskeleton resulted in reduction of receptor sensitivity.
3) The structure of the stretch receptor was examined in locust wings. The cell body of the stretch receptors is large (up to 50 mum) and extends many dendrites, which must be receptor sites. Actin filaments were densely localized in the dendritic regions.
4) The data obtained in the present study suggest that three types of the insect mechanoreceptors possess their specific primary processes of the mechano-electric transduction, which is closely related to specific organization of cytoskeleton in the receptor region.
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