アイテム詳細

要旨

Cognition emerges when the brain transforms sensory information into abstract mental constructs or flexible internal representations. This internal cognitive representation of the external world is the basis for abstract thought, reasoning, and generalized intelligence. A prime example of this process is the mammalian ability to Data Blitz Talks 9 form spatial cognitive maps of the external environment. However, evidence for spatial maps (e.g. place cells) has yet to be convincingly identified in any species outside of mammals and birds. Thus, when and how spatial cognition emerged during evolution remains a central mystery of neuroscience. Using a state-of-the-art tracking microscope to image brain-wide activity at cellular resolution in freely swimming larval zebrafish, we computed the spatial information of neurons throughout the zebrafish brain. We find that the zebrafish telencephalon contains a network of place cells forming an internal representation of space. The place cell network in zebrafish exhibits striking similarities to mammals, as evidenced by multimodal integration of self-motion and visual input, experience- dependent refinement of the spatial map, and spontaneous offline reactivation of place cell ensembles. This recent discovery raises the possibility that spatial cognition arose in a compact circuit over 400 million years ago, setting up an initial condition for the subsequent elaboration and expansion of cognitive capabilities in mammals. Furthermore, the compact brain of larval zebrafish presents a unique opportunity to combine simultaneous neural recordings of the entire spatial computational network with the complete synapse- scale connectome of the underlying circuitry, to uncover the mechanistic principles underlying spatial cognition.