Brain cell map reveals genetic links to neurodegenerative diseases

Scientists have developed a massive genetic map of the human prefrontal cortex, analyzing more than 6 million cells from nearly 1,500 individuals ranging in age from infants to 108 years old. By utilizing single-nucleus RNA sequencing and new transcriptomic imputation models (snTIMs), researchers can now predict how genetics regulate gene expression within specific, isolated cell populations such as neurons, glial cells, and immune cells.

This high-resolution mapping has revealed thousands of gene-disease associations that were previously invisible to traditional analysis. The study identified distinct biological pathways for various conditions: Alzheimer's disease shows strong links to microglia dysfunction, while schizophrenia and bipolar disorder are associated with dysregulation in inhibitory neurons. Additionally, the research highlights pleiotropic effects, where a single gene can influence different diseases depending on the specific cell type in which it operates.

Notably, the research incorporates diverse ancestral backgrounds, including European, African, and admixed American populations, moving beyond the historical focus on European-descended groups. By integrating these data with the Million Veteran Program, researchers confirmed that the genetic dysregulations associated with these neuropsychiatric and neurodegenerative diseases are conserved across different ancestries.