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Large-scale Three-dimensional Imaging of Cellular Organization in the Mouse Neocortex
Published on: September 5, 2018
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Reallocation of Olfactory Cajal-Retzius Cells Shapes Neocortex Architecture.
Cristina A de Frutos1, Guy Bouvier2, Yoko Arai3
1Ecole Normale Supérieure, PSL Research University, Institut de Biologie de l'ENS (IBENS), INSERM, CNRS, Brain Development and Plasticity Team, F-75005 Paris, France.
Neuron
|October 4, 2016
Summary
Neocortical development involves Cajal-Retzius (CR) neurons migrating from the olfactory system to maintain density. This process is crucial for proper neocortical circuit wiring and layer 1 architecture.
Area of Science:
- Neuroscience
- Developmental Biology
- Neuroanatomy
Background:
- The neocortex expands significantly during development, but the mechanisms maintaining its architecture are not fully understood.
- Cajal-Retzius (CR) neurons are critical for assembling cortical circuits and typically reside in the superficial layers.
Purpose of the Study:
- To investigate how Cajal-Retzius (CR) neurons maintain their dense superficial distribution within the expanding neocortex.
- To understand the role of CR cell density in neocortical circuit formation and layer 1 architecture.
Main Methods:
- Investigated CR neuron migration patterns using mouse models.
- Employed mouse genetics to study the impact of CR cell density on cortical architecture.
- Analyzed the excitation/inhibition ratio in neocortical networks.
Main Results:
- CR cell density is maintained by activity-dependent importation of CR cells from the olfactory system.
- These CR cells migrate into the neocortex after serving as guideposts in the olfactory system.
- Reduced CR cell density significantly impacts layer 1 architecture, leading to an imbalance in the excitation/inhibition ratio.
Conclusions:
- Neurons can re-enter migration post-positioning to fulfill sequential developmental roles in different brain regions.
- This atypical migration is essential for regulating CR cell density during neocortical growth.
- Proper CR cell density is vital for the correct wiring of neocortical circuitry.
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