The Structural Model: a theory linking connections, plasticity, pathology, development and evolution of the cerebral...

Area of Science:

• Neuroscience
• Comparative Anatomy
• Evolutionary Biology

Background:

• The classical theory of cortical systematic variation is observed across diverse mammal groups, suggesting a conserved evolutionary plan (bauplan).
• Understanding this variation is key to deciphering cortical organization and function.
• Previous models have not fully integrated this systematic variation into a predictive framework.

Purpose of the Study:

• To introduce and validate a Structural Model based on systematic cortical variation.
• To provide a platform for testing hypotheses about cortical organization and function across species.
• To link cortical types to functional and pathological outcomes.

Main Methods:

• Categorization of the cortical architectonic continuum into discrete 'cortical types' based on laminar structure (agranular, dysgranular, eulaminate).
• Analysis of the relationship between cortical types and features like connectivity, plasticity, gene expression, and disease vulnerability.
• Tracing the developmental origins of cortical types.

Main Results:

• The Structural Model successfully links cortical types to laminar patterns, connection strength, plasticity, marker distribution, and disease vulnerability.
• Phylogenetically ancient limbic cortices are characterized as agranular or dysgranular.
• Eulaminate cortices possess six layers, with variations in number and elaboration across species.
• The developmental origins of cortical types help explain disease variability.

Conclusions:

• The Structural Model offers a predictive framework for understanding cortical organization and evolution.
• Cortical types provide a basis for linking structure to function, development, and disease.
• This model advances our understanding of the conserved bauplan of the mammalian cortex.