Functional Clusters, Hubs, and Communities in the Cortical Microconnectome

Area of Science:

• Neuroscience
• Computational Neuroscience
• Systems Neuroscience

Background:

• Macroscopic brain studies show network relationships across scales.
• Understanding neuronal network structures at different scales remains unknown.

Purpose of the Study:

• To investigate the scale-dependent organizational structures in neuronal networks.
• To determine the robustness of different network structures against perturbations.

Main Methods:

• Simultaneous recording of up to 500 neurons from rodent somatosensory cortex slice cultures.
• Measurement of directed effective networks using transfer entropy.
• Analysis of connectivity structures at cluster (3-6 neurons) and community (tens to hundreds of neurons) scales.

Main Results:

• Identified significantly more connections within neuronal clusters than expected by chance.
• Observed a long-tailed degree distribution, indicating the presence of network hubs.
• Detected 2-3 significant communities at the larger network scale.
• Demonstrated that communities exhibit greater robustness than clusters against connection shuffling.

Conclusions:

• The cortical microconnectome exhibits specific, scale-dependent organization.
• Differences in robustness between clusters and communities reveal distinct structural properties.
• Findings provide insights into the microconnectome's resilience to damage.