| 研究課題/領域番号 |
18F18807
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| 研究機関 | 総合研究大学院大学 |
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研究代表者 |
蟻川 謙太郎 総合研究大学院大学, 先導科学研究科, 教授 (20167232)
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| 研究分担者 |
ILIC MARKO 総合研究大学院大学, 先導科学研究科, 外国人特別研究員
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| 研究期間 (年度) |
2018-11-09 – 2021-03-31
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| キーワード | Intracellular recording / Insect / Vision / Lamina / Spectral sensitivity / Spectral opponency / Papilio xuthus / Modelling |
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| 研究実績の概要 |
From the beginning of the fellowship we have made good progress in the overall plan of the program. Based on previous findings in the field we have decided on the approach to the research question. We have obtained intracellular recordings from photoreceptors (PR) and lamina monopolar neurons (LMC) which exhibited opponency in some parts of the spectra. Using special research protocols which were devised to test the response to gradually long- or short-pass filtered light, show a possibility of spectral tuning to these kinds of visual stimuli. The results are promising, as some of the PR cells show potential tuning. The fellow has been to Ljubljana, visiting the lab of Gregor Belušič, where he conducted similar experiments and obtained similar data, which is a good reassurance in the quality of both laboratories. To shine some more light on the topic we modeled PR cell responses in Matlab using PR spectral sensitivity curves, PR intensity curves and interommatidial synapse connections between PR in all three ommatidial types in Papilio xuthus. The model predictions explained the measured data well. The LedSynth device, which is currently operational in the laboratory has 12 color channels, with which we obtained promising preliminary data but the number of channels is relatively low for the purpose we need and needs an upgrade. We have already started the process, which will be explained in the <Plan for next year> section of this form.
We have also applied to participate in the ICIV 2019 conference on invertebrate vision in Sweden and are awaiting a response.
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
1: 当初の計画以上に進展している
理由
We have obtained preliminary data and devised specialized protocols, which show a lot of potential. As the visual system of P. xuthus is complicated we need to take the spatial factor into account. We were thinking of implementing a DLP (digital light projector) based light stimulation protocol, but as the device would be difficult to implement we need to run some additional preliminary data before deciding. The focus will therefore be on using an upgraded LedSynth with 21 spectral channels, mounted on a goniometric movable arm to obtain data from off-axis locations. Based on these data we will extend the prediction power of the model and decide if the DLP is the best way to go. The main advantages of the DLP would be fast changes of stimulus position, multiple stimuli, stimulus size control and less movable parts, which together would increase the success rate of the experiments.
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| 今後の研究の推進方策 |
We plan upgrading the current 12-channel LedSynth to a 21-channel version to gather better data sets for opponent interactions in single ommatidia and also neighboring ommatidia. We have already prepared the LEDs and ordered the remaining materials, necessary for the assembly (mounts and electronics). Using the new device, we will also measure spectral sensitivity curves of single PR and LMC cells with on- and off-axis stimulation in an array pattern spanning several angular degrees to obtain useful data for increasing the prediction power of the model and better utilize the synapse connection matrix. We believe that the opponency of single photoreceptors results from opponent influence of more than just the PR in the same ommatidium. If these experiments yield solid data we will likely decide on implementing a DLP light stimulus device for faster and more precise light stimulation and investigate the multi-ommatidial influence on single photoreceptor spectral sensitivity.
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