The functional organization of excitation and inhibition in the dendrites of mouse direction-selective ganglion cells
Abstract
Recent studies indicate that the precise timing and location of excitation and inhibition (E/I) within active dendritic trees can significantly impact neuronal function. How synaptic inputs are functionally organized at the subcellular level in intact circuits remains unclear. To address this issue, we took advantage of the retinal direction-selective ganglion cell circuit, where tuned inhibition is known to shape non-directional excitatory signals. We combined two-photon calcium imaging with genetic, pharmacological, and single-cell ablation methods to examine the extent to which inhibition 'vetoes' excitation at the level of individual dendrites of direction-selective ganglion cells. We demonstrate that inhibition accurately shapes direction selectivity independently within small dendritic segments (<10 μm) with remarkable accuracy. This suggests that the parallel processing schemes proposed for direction encoding could be more fine-grained than previously envisioned.
Data availability
All data generated or analyzed during this study are included in the manuscript and supporting files. Source data files have been provided for all Figures
Article and author information
Author details
Funding
Canadian Institutes of Health Research (159444)
- Gautam Bhagwan Awatramani
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Reviewing Editor
- Markus Meister, California Institute of Technology, United States
Ethics
Animal experimentation: All procedures were performed in accordance with the Canadian Council on Animal Care and approved by the University of Victoria's Animal Care Committee (Protocol 2016 (15).
Version history
- Received: October 22, 2019
- Accepted: February 24, 2020
- Accepted Manuscript published: February 25, 2020 (version 1)
- Version of Record published: March 13, 2020 (version 2)
Copyright
© 2020, Jain 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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