演題詳細
Symposium
小規模モデル動物による脳機能の基本原理へのアプローチ
Elucidation of principle of neural circuits using small circuits
開催日 | 2014/9/12 |
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時間 | 17:10 - 19:10 |
会場 | Room F(302) |
Chairperson(s) | 上川内 あづさ / Azusa Kamikouchi (名古屋大学大学院理学研究科 生命理学専攻 / Graduate School of Sciene, Nagoya University, Japan) 森 郁恵 / Ikue Mori (名古屋大学大学院理学研究科 / Graduate School of Sciene, Nagoya University, Japan) |
触角の動きパターンはショウジョウバエの脳内で空間表現される
A spatial representation of the pattern of antennal movement in the fruit-fly brain
- S2-F-3-4
- 上川内 あづさ / Azusa Kamikouchi:1,2 松尾 絵倫子 / Eriko Matsuo:1 山田 大智 / Daichi Yamada:1
- 1:名古屋大学 / Nagoya University, Japan 2:科学技術振興機構さきがけ / PREST, Japan Science and Technology Agency, Japan
How does the brain encode sensory information? To approach its answer, we use a mechanosensory system of the fruit fly as a model system. Fruit flies respond behaviorally to sound, gravity, and wind. Johnston's organ (JO), the antennal ear of the fly, serves as a sensory organ to detect these mechanosensory stimuli. Specific subgroups of sensory neurons in JO, so-called JO neurons subgroups, work as sensors for vibrations and static deflections of the antennal receiver. Five subgroups of JO neurons, subgroups A to E, reportedly project to one of the five AMMC zones, zones A to E, in the brain. Despite intensive analyses on the functional role of these subgroups, the function of subgroup-D JO neurons, which show unique anatomic characteristics when compared with other subgroups of JO neurons, is little understood. Here, we explored the physiologic properties of subgroup-D JO neurons by using GCaMP3-based calcium imaging. In contrast to other subgroups of JO neurons, all of which were reportedly activated either by vibrations (subgroups A and B) or by static deflections (subgroups C and E), subgroup-D JO neurons responded to both stimuli; vibrating at around 100-200 Hz and anterior deflection of the receiver selectively evoked strong calcium response in subgroup-D JO neurons in the brain. This finding clearly revealed that subgroup-D JO neurons could encode the position and movement of the antennal receiver. The five anatomically defined zones as projection targets of JO neurons are now defined as three functionally distinct groups: (1) a primary vibration center (zones A and B), (2) a primary deflection center (zones C and E), and (3) a primary vibration and deflection center (zone D). A fly brain thus could encode information about complex movements of the antennal receiver by expanding its movement into 5-dimensional space in the fly brain.