摘要

Spontaneous, patterned neuronal activity has been closely linked to mechanisms shaping the early nervous system development and is suggested to play a key role in the fine-tuning of developing circuits. However, little is known about how patterned activity emerges de novo and what factors control this maturation process. Major limitations to this end have been (1) the lack of functional recordings at the whole-circuit level with single-neuron resolution and throughout the period over which patterned activity emerges, and (2) the technical challenge of mapping the origin and roles of neurons participating in the functional maturation process back to neurogenesis, when neurons are first born. Here, we used high-speed light-sheet microscopy to image the emergence of patterned activity in the developing spinal cord of embryonic zebrafish. We developed imaging assays and computational tools to record and analyze calcium activity in all post-mitotic neurons for a large fraction of the developing spinal cord at a temporal resolution of 4 Hz with cell type-specificity. The data show that spinal cord neurons undergo a rapid transition from sporadic single-neuron activity to ipsi-laterally correlated and contra-laterally anti-correlated activity between 18 and 22 hours post fertilization: Ipsilateral synchronization is initiated as local patterns that potentially arise from leader motoneurons, and ablation experiments suggest that global synchronization forms when the network span across a sufficiently large number of segments. Late activation of the dorsal commissural interneurons play an important role in establishing the phase-lag between left and right hemi-segments. Moreover, combining functional imaging with whole-embryo developmental imaging during neurogenesis revealed multiple conserved links between developmental anatomy and cell lineages with the maturation profile of active neurons in the spinal cord.

 

报告人简介

Dr Yinan Wan is working as a postdoctoral associate, in Keller’s group at Howard Hughes Medical Institute/Janelia Research Campus. She received her PhD degree from the University of Cambridge in May 2017. Her research interests include “Development of Functional Circuits in the Zebrafish” and “Embryonic and Postembryonic Nervous System”. She has published several papers in Developments, Nature Methods, Nature Biotechnology, etc.