| Project/Area Number |
07640904
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
動物生理・代謝
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| Research Institution | Kyushu Institute of Design |
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Principal Investigator |
YAMASHITA Shigeki Kyushu Institute of Design, Faculty of Design, Professor, 芸術工学部, 教授 (30091250)
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| Co-Investigator(Kenkyū-buntansha) |
NAKAMURA Takiko kyushu Institute of Design, Faculty of Design, Assistant, 芸術工学部, 教務員 (70274545)
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| Project Period (FY) |
1995 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 1997: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1996: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1995: ¥1,000,000 (Direct Cost: ¥1,000,000)
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| Keywords | Spider / Eye / Photoreceptor / Cerebral Photosensitive Neuron / Phototaxis / Sensitivity / Efferent Neuron / Circadian Rhythm / 夜行性 / 昼行性 / 視覚行動 |
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| Research Abstract |
1. The anterior median (AM) eye of Argiope has both lower sensitive photoreceptors and higher sensitive ones, and the latter show a circadian oscillation of sensitivity under a constant darkness. Argiope appear to be active both during the day and at night. In the present study, we examined circadian oscillation of sensitivity of the AM eye of a nocturnal spider Araneus and a diurnal spider Menemerus by recording ERGs from the intact spider. The AM eye of Araneus showed a marked circadian oscillation of sensitivity but that or Menemerus showed no circadian oscillation. It was suggested that the greater parts of photoreceptors in the AM eye or Araneus and those of Menemerus were higher sensitive photoreceptors and lower sensitive ones, respectively.
2. Photoreceptor responses of spiders are controlled by efferent signals in the optic nerve. The frequency of efferent optic nerve impulses for Argiope increased during illumination of the brain. In contrast, the frequency of efferent optic nerve impulses for Araneus decreased during illumination or the brain. In Menemerus, we observed no efferent optic nerve signals.
3. Phototactic behaviors of spiders which walked on a Y-maze globe were examined. Argiope tended to turn at Y-arms away from a test light on a dark-backgrounds (negative phototaxis), but toward the light on a light-background (positive phototaxis). Both on dark- and light-backgrounds, Araneus showed a negative phototaxis, but Menemerus showed a positive phototaxis.
4. We observed that Araneus show a marked positive phototaxis transiently after the cessation of background illumination for l2 hours. It was suggested that the activation of efferent neurons plays a role in phototactic behavior.
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