Modeling and simulation of neocortical micro- and mesocircuitry (Part I, anatomy)

Area of Science:

• Neuroscience
• Computational Biology
• Systems Neuroscience

Background:

• Neocortical function relies on microcircuit motifs and interregional connectivity.
• Understanding these complex networks is crucial for deciphering brain function.

Purpose of the Study:

• To develop a data-driven computational model of rat primary somatosensory cortex anatomy.
• To integrate whole-brain scale data with cellular and subcellular specificity.
• To analyze the interplay between local and interregional connectivity.

Main Methods:

• Construction of a computational model with 4.2 million neurons and 14.2 billion synapses.
• Integration of whole-brain scale data into a digital brain atlas.
• Analysis of neuron morphology and placement to determine connectivity patterns.

Main Results:

• The model successfully reproduces targeting by Somatostatin-positive (Sst+) neurons.
• Additional specificity is needed to accurately model Parvalbumin-positive (PV+) and Vasoactive Intestinal Polypeptide-positive (VIP+) interneuron targeting.
• Connectivity is characterized by local clusters linked by Layer 5 hub neurons, indicating integrated local and interregional networks.

Conclusions:

• Local and interregional connectivity are intrinsically linked, forming inseparable networks.
• The developed computational model provides a valuable resource for simulation-based neuroscience research.
• The model is openly available to the scientific community for further investigation.