ショウジョウバエ脳における睡眠状態依存的感覚情報処理とメカニズムの解明

2019 Fiscal Year Annual Research Report

• Project/Area Number: 19F19718
• Research Institution: Institute of Physical and Chemical Research
• Principal Investigator: 風間 北斗 国立研究開発法人理化学研究所, 脳神経科学研究センター, チームリーダー (90546574)
• Co-Investigator(Kenkyū-buntansha): KIRSZENBLAT LEONIE 国立研究開発法人理化学研究所, 脳神経科学研究センター, 外国人特別研究員
• Project Period (FY): 2019-07-24 – 2021-03-31
• Keywords: sleep / olfaction / calcium imaging / optogenetics / Drosophila

Outline of Annual Research Achievements

Sleep is a state of quiescence during which an animal loses awareness of the external world. Although sleep is important for many brain functions, the mechanisms that underpin sleep and its functions are poorly understood. In this study, we will investigate the neural mechanisms by which the brain suppresses perception during sleep, with a focus on the Drosophila olfactory system. We will establish a system in which we can image neural activity of olfactory circuits during sleep and investigate how sleep alters odor representations. Next, we will examine the neural mechanisms underlying this sleep-dependent olfactory processing. Finally, we will examine the functional impact of sleep on olfactory behaviour. This study aims to reveal principles of sleep functions in sensory perception.
To this end, we have established a system in which we can image neural activity of olfactory circuits of a fly during awake or sleep. We built a system to track the behavior of the fly under a two-photon microscope. We also built a system comprising a camera, behavioral arenas, motors, and online image analysis software that can control the level of sleep deprivation of multiple individual flies. Furthermore, we established a fly line in which sleep can be induced using optogenetics while neural activity can be recorded from neurons comprising the olfactory circuit.

Current Status of Research Progress

2: Research has progressed on the whole more than it was originally planned.

Reason

Because we were able to build a system (1) to image neural activity of olfactory circuits in a fly during awake or sleep, (2) to track the behavior of individual flies under a microscope, and (3) to sleep deprive the flies as planned. Also, fly lines required for simultaneously controlling sleep and measuring neural activity are ready.

Strategy for Future Research Activity

Using the resources and devices we’ve made in the first fiscal year, we plan to investigate whether neural responses to odors are altered during sleep, following sleep, or following sleep deprivation in the primary and secondary olfactory processing centers. If we find state-dependent changes in olfactory responses, we will further examine the underlying cellular and circuit mechanisms using genetic approaches.