Laminar-specific cortico-cortical loops in mouse visual cortex
Abstract
Many theories propose recurrent interactions across the cortical hierarchy, but it is unclear if cortical circuits are selectively wired to implement looped computations. Using subcellular channelrhodopsin-2-assisted circuit mapping in mouse visual cortex, we compared feedforward (FF) or feedback (FB) cortico-cortical synaptic input to cells projecting back to the input source (looped neurons) with cells projecting to a different cortical or subcortical area. FF and FB afferents showed similar cell-type selectivity, making stronger connections with looped neurons than with other projection types in layer (L) 5 and L6, but not in L2/3, resulting in selective modulation of activity in looped neurons. In most cases, stronger connections in looped L5 neurons were located on their apical tufts, but not on their perisomatic dendrites. Our results reveal that cortico-cortical connections are selectively wired to form monosynaptic excitatory loops and support a differential role of supragranular and infragranular neurons in hierarchical recurrent computations.
Data availability
All data is publicly available on Dryad https://doi.org/10.5061/dryad.1ns1rn8r7
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Laminar-specific cortico-cortical loops in mouse visual cortexDryad Digital Repository, doi:10.5061/dryad.1ns1rn8r7.
Article and author information
Author details
Funding
La Caixa Banking Foundation (LCF/PR/HR17/52150005)
- Leopoldo Petreanu
Fundação para a Ciência e a Tecnologia (LISBOA-01-0145-FEDER 030328)
- Leopoldo Petreanu
Fundação para a Ciência e a Tecnologia (Congento LISBOA-01-0145-FEDER-022170)
- Hedi Young
- Beatriz Belbut
- Margarida Baeta
- Leopoldo Petreanu
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Ethics
Animal experimentation: All procedures were reviewed and performed in accordance with the Champalimaud Centre for the Unknown Ethics Committee and approved by the Portuguese Veterinary General Direction.(Ref.No.0421/000/000/2019)
Copyright
© 2021, Young 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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