1988 Fiscal Year Final Research Report Summary
Development of laser apparatus for selective elimination of nerve cells and cell portions from neural circuits
| Project/Area Number |
61840023
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| Research Category |
Grant-in-Aid for Developmental Scientific Research
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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 | Hokkaido UNiversity |
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Principal Investigator |
MITUHIKO Hisada Hokkaido University, Fac. of Science, 理学部, 教授 (70000768)
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| Co-Investigator(Kenkyū-buntansha) |
TAKASHI Nagao Hokkaido University,, 実験生物センター, 助手 (70113595)
MASAKAZU Takahata Hokkaido University, Fac. of Science, 理学部, 助手 (10111147)
NORIYO Suzuki Hokkaido University, Fac. of Science, 理学部, 講師 (10001851)
TATEO Shimozawa Hokkaido University, Fac. of Science, 理学部, 助教授 (10091464)
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| Project Period (FY) |
1986 – 1988
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| Keywords | He-Cd laser / cell destruction / nerve cells / neurites / neural circuit / 神経回路 |
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| Research Abstract |
A laser apparatus for selectively destroying parts of nerve cells has been devised. This apparatus is basically a dissecting microscope combined with short wave-length laser (441.6nm, He-Cd) illumination. The system can be converted into either an eplllluminating fluorescence or an intense microbeam irradiation apparatus by displacing a single lens. Combined with low level vital staining of neurons with Lucifer yellow dye through the recording electrode, the apparatus facilitates the identification of the penetrated neuron while its activity is recorded, and enables the in situ destruction and subsequent removal of the neuron or a part of it from the neural circuit.
The apparatus was applied to the extensor inhibitory motoneuron in the 4th abdominal gangiion which had output effect to its contralateral homolog. The motoneuron was penetrated with a Lucifer-filled electrode with which its spontaneous activity and the antidromic spike to second root stimulation were recorded. After the physiological test, the Lucifer was injected into the cell iontophoretically with -10nA DC. The lucifer-filled cell was examined with the laser epiillumination in order to identify morphologically that it was the extensor inhibitor. When the axonal portion of the motoneuron was selectively irradiated by the intense microbeam. the cell could no longer propagate its orthodromic action potentials over the irradiated portion. The rest of the cell in the ganglion, however, operated normally. Applying this method to the uropod motor system of crayfish, we could also confirm that certain branches of nonspiking interneurons would operate as the input site while others act as the output region.
The experimental results show that the device daveloped in the current project is extremely useful to the study of individual neurite function in a single cell.
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Research Products
(28 results)
