2015 Fiscal Year Annual Research Report
| Project/Area Number |
15F14409
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| Research Institution | Institute of Physical and Chemical Research |
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Principal Investigator |
林 康紀 国立研究開発法人理化学研究所, 脳科学総合研究センター, チームリーダー (90466037)
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| Co-Investigator(Kenkyū-buntansha) |
LUCHETTI ALESSANDRO 国立研究開発法人理化学研究所, 脳科学総合研究センター, 外国人特別研究員
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| Project Period (FY) |
2015-04-24 – 2017-03-31
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| Keywords | セロトニン / in vivo イメージング / バーチャルリアリティ / 海馬 |
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| Outline of Annual Research Achievements |
During my work, I firstly focused on the technical challenge of obtaining stable imaging from very thin structures in the behaving, head fixed animals. Several combinations of viral vectors, transgenic lines and imaging conditions were tested in order to find ways to obtain strong signal to noise ratio and achieve good resolution images at a high frame rate. I also aimed to minimize the imaging artifacts generated by several factors such as non-specific expression, z axis motion, bleaching, etc. Then came the task of investigating different neuromodulatory systems that synapse into the CA1. By combining transgenic lines and Cre-expression dependent viral constructs, I tried to image dopaminergic, noradrenergic and serotonergic input coming from the Ventral Tegmental Area (VTA), Locus Coeruleus (LC) and Median Raphe (MR) respectively.
Interestingly, the serotonergic fibers in the CA1 showed an unexpected firing pattern that, to our knowledge, is not described in any of the current literature investigating Median Raphe activity. Specifically, I identified a very robust bursting activity by serotonergic fibers in CA1 when the animal is about to start running. Early results also suggest these fibers preferentially fire when the animal is crossing between different segments of the linear track, suggesting that these fibers play a role in compartmentalizing space. I now wish to corroborate these findings by using optogentics systems to manipulate the serotonergic network during spatial learning.
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
During this fiscal year we will start to record how reward events affect neuromodulatory activity and CA1 ensamble activity. Activity if recorded using a head fixed virtual reality setup in which the mouse runs on a air-suspended ball while under a 2 photon microscope.
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| Strategy for Future Research Activity |
Based on our findings we will modulate neuromodulatory activity using drugs or artifical stimulation to see if we can mimick the effect of reward on the CA1 neuronal activity. The artifical stimulation will be achieved by optogenetics means or using stimulating electrodes. Analysis of data and publication of results.
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