Direct translation of climbing fiber burst-mediated sensory coding into post-synaptic Purkinje cell dendritic calcium
Abstract
Climbing fibers (CFs) generate complex spikes (CS) and Ca2+ transients in cerebellar Purkinje cells (PCs), serving as instructive signals. The so-called 'all-or-none' character of CSs has been questioned since the CF burst was described. Although recent studies have indicated a sensory-driven enhancement of PC Ca2+ signals, how CF responds to sensory events and contributes to PC dendritic Ca2+ and CS remains unexplored. Here, single or simultaneous Ca2+ imaging of CFs and PCs in awake mice revealed the presynaptic CF Ca2+ amplitude encoded the sensory input's strength and directly influenced post-synaptic PC dendritic Ca2+ amplitude. The sensory-driven variability in CF Ca2+ amplitude depended on the number of spikes in the CF burst. Finally, the spike number of the CF burst determined the PC Ca2+ influx and CS properties. These results reveal the direct translation of sensory information-coding CF inputs into PC Ca2+, suggesting the sophisticated role of CFs as error signals.
Data availability
All data generated or analysed during this study are included in the manuscript and supporting files. Source data files have been provided for Figures 1 through 5. Code has been made available via GitHub at https://github.com/NeuRoh1/Calcium_signal_processing .
Article and author information
Author details
Funding
National Research Foundation of Korea (2018R1A5A2025964)
- Sang Jeong Kim
National Research Foundation of Korea (2017M3C7A1029611)
- Sang Jeong Kim
National Research Foundation of Korea (2016R1D1A1A02937329)
- Sun Kwang Kim
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Ethics
Animal experimentation: This study was performed in strict accordance with the recommendations in the Guide for the Care and Use of Laboratory Animals of the National Institutes of Health. All of the animals were handled according to approved institutional animal care and use committee (IACUC) protocols (#SNU-111214-6-3) of the Seoul National University. The protocol was approved by the Committee on the Ethics of Animal Experiments of the Seoul National Universtiy. All surgery was performed under intraperitoneal injections of Zoletil/Rompun mixture (30 mg / 10 mg/kg), and every effort was made to minimize suffering.
Copyright
© 2020, Roh et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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