The relationship between transcription and eccentricity in human V1

Area of Science:

• Neuroscience
• Genomics
• Human Brain Anatomy

Background:

• Gene expression gradients are known to organize the human cerebral cortex.
• The role of transcription in organizing individual brain regions remains unclear.
• Challenges include anatomical consistency and dense tissue sampling in humans.

Purpose of the Study:

• To investigate the relationship between gene expression and functional organization within human primary visual cortex (V1).
• To determine if transcription gradients operate at the level of single cortical areas.
• To compare gene expression patterns in V1 with those organizing cortical areas.

Main Methods:

• Analysis of differential gene expression in human primary visual cortex (V1).
• Enrichment analyses of identified genes.
• Histological validation using Nissl-stained postmortem occipital cortex sections.

Main Results:

• A relationship was found between differential gene expression and the cortical layout of eccentricity in human V1.
• Identified genes are distinct from those organizing the visual processing hierarchy.
• Genes related to inhibitory interneurons, ion channels, and cellular projections were expressed more in foveal than peripheral V1, predicting higher foveal tissue density, which was histologically validated.

Conclusions:

• Transcription gradients operate at multiple spatial scales in the adult human brain, including within single cortical areas.
• Differential gene expression contributes to the functional organization of human V1.
• Findings align with organizational patterns observed in non-human primates and suggest a multi-scale role for transcription in brain organization.