Genetic mapping and evolutionary analysis of human-expanded cognitive networks

Area of Science:

• Neuroscience
• Evolutionary Biology
• Genetics

Background:

• Cognitive brain networks, including the default-mode network (DMN), are crucial for human cognition.
• The human brain has undergone rapid evolutionary cortical expansion, especially in higher-order networks.

Purpose of the Study:

• To investigate the relationship between the evolutionary expansion of human cognitive networks and gene expression.
• To identify specific genes and their functions associated with these networks and human cognitive evolution.

Main Methods:

• Comparative transcriptomics analysis across humans, chimpanzees, and macaques.
• Analysis of gene expression patterns in higher-order cognitive networks, focusing on the DMN.
• Association studies linking gene expression with cognitive traits and mental conditions.

Main Results:

• Human-accelerated genes (HAR genes) are differentially expressed in higher-order cognitive networks, notably the DMN, in humans compared to other primates.
• Genes highly expressed in the DMN are implicated in synapse and dendrite formation.
• HAR and DMN genes correlate with variations in DMN activity, intelligence, sociability, and susceptibility to schizophrenia and autism.

Conclusions:

• The expansion of higher-order functional networks supporting advanced cognitive abilities is a significant area of genetic change in recent human evolution.
• HAR genes play a critical role in shaping human-specific cognitive functions and brain network development.