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Updated: May 23, 2026
09:55
Large-scale Three-dimensional Imaging of Cellular Organization in the Mouse Neocortex
Published on: September 5, 2018
Columnar interactions determine horizontal propagation of recurrent network activity in neocortex
Jason C Wester1, Diego Contreras
1Department of Neuroscience, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104, USA.
Summary
Interactions between supragranular and infragranular cortical layers are crucial for propagating neural activity. Layer 5 circuits sustain and propagate activity horizontally, while Layer 2/3 amplifies it.
Area of Science:
- Neuroscience
- Computational Neuroscience
- Systems Neuroscience
Background:
- The neocortex features intricate vertical and horizontal circuits governing neural activity.
- Understanding local population interactions within these circuits remains a challenge.
Purpose of the Study:
- Investigate interactions between laminar and horizontal circuits in the neocortex.
- Elucidate the roles of different cortical layers in generating and propagating activity.
Main Methods:
- Utilized rat thalamocortical slices in vitro with self-sustained recurrent activity (up-states).
- Employed intracellular recordings and voltage-sensitive dye imaging.
- Used focal TTX injections to selectively block local circuit activity.
Main Results:
- Identified a preferential activation sequence: Layer 4 → Layer 2/3 → Layer 5.
- Layer 5 sustains activity independently and is essential for horizontal propagation.
- Layer 2/3 enhances activity in Layer 5 but is inefficient for horizontal propagation alone.
- Loss of Layer 2/3 delays horizontal propagation mediated by Layer 5.
Conclusions:
- Columnar interactions between supragranular (L2/3) and infragranular (L5) layers are vital for neocortical activity propagation.
- Supragranular and infragranular circuits cooperate to shape cortical activation patterns observed in vivo.
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