第1320回生物科学セミナー
Studying Neuronal Mechanisms of Decision-Making and Learning in Hydra vulgaris
山本 渉 博士（Biological Sciences, Columbia University, Yuste Lab, New York, USA）
2020年02月05日(水) 16:00-17:00 理学部3号館 326号室
Sensory cues (e.g. food or threat) can cause animals to quickly switch behaviors based on simple cost- benefit computation that is crucial for survival. However, the underlying neural-circuit mechanisms and corresponding brain-wide interactions responsible for sensorimotor integration and decision-making have remained largely unclear. This is partly due to the lack of experimental access to record the multiple brain regions simultaneously at single-cell resolution.
To address this, we use a cnidarian Hydra vulgaris for the following reasons: i) Hydra has one of the simplest nervous systems, called a nerve net, which enables imaging the entire nervous system during complex behaviors including feeding and locomotion. ii) The activity of each neuronal circuit named CB, RP1, and RP2 in Hydra is associated with a specific motor behavior. These properties, and recent background work imaging the entire neuronal and muscle activity and reconstructing the entire behavioral repertoire, make Hydra an ideal model for imaging the complete neuronal activity during behavior.
In this seminar, I would like to present our recent results obtained using Hydra expressing GCaMP6s in neurons focusing on two behaviors: locomotion and feeding. First, we found how Hydra use neuronal circuit to decide to locomote, a series of motor behavior. Second, we found Hydra exhibits a basic types of learning such as habituation during feeding, a fixed action pattern that includes tentacle writhing and mouth opening.
