1993 Fiscal Year Final Research Report Summary
Physiological and behavioral studies of changes in absolute and spectral sensitivities on spiders eyes
| Project/Area Number |
03640608
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
動物発生・生理学
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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) |
ARITA Fumiko Kyushu Institute of Design, Faculty of Design, Assistant, 芸術工学部, 教務員 (30253545)
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| Project Period (FY) |
1991 – 1993
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| Keywords | Spider / Eye / Photoreceptor / Sensitivity / Cerebral Photosensitive Neuron / Efferent Fiber / Neutotransmitter / Octopamine |
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| Research Abstract |
1. The spectral sensitivity of the ocellus in the cucumber looper moth, Anadevidia peponis, was investigated by recording electroretinograms (ERGs). The peak sensitivities were observed at 340 nm in the ultraviolet and at 520-540 nm in the green. Selective spectral adaptation revealed the existence of at least two receptor types in the ocellar retina. The ratio of green to ultraviolet sensitivities for that ocellus whose ocellar nerve was cut was higher than for an intact ocellus. It is suggested that efferent signals which control the spectral sensitivity of the ocellus are present in the ocellar nerve.
2. The effect of monochromatic light applied to the brain on the phototactic behavior of the tethered orb weaving spiders Argiope amoena and Nephila clavata was examined. It is suggested that cerebral photosensitive neurons which have a maximum sensitivity at about 440 nm play a role in phototactic behavior.
3. The photoreceptor response of the anterior lateral eyes of the orb weaving spiders, Argiope bruennichii and A.Amoena were examined by recording extracellular ERGs and intracellular receptor potentials. The eyes showed a circadian oscillation in the photoreceptor response which was mediated by efferent impulses in the optic nerve. During the "night state", the sensitivity of photoreceptors increased and the waveform of receptor potentials broadened as compared with those for the "day state". Octopamine, which has been reported as an efferent neurotransmitter of circadian rhythms in the Limulus and the scorpion eyes, mimicked endogenous efferent neurotransmission in the spider eyes, i.e., it increased the sensitivity of photoreceptors and broadened the waveform of receptor potentials. The results suggest that, in the spider eyes also, octopamine is an efferent neurotransmitter.
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