Researchers have assembled the most extensive map to date of gene activity in the human prefrontal cortex, a brain region essential for planning, decision‑making and emotional regulation. By analysing more than 6.3 million individual cells from nearly 1,500 donated brains, the team created a resource that could accelerate studies of neurodegenerative and psychiatric illnesses.
Scale and methodology
The effort, coordinated by the PsychAD Consortium—a National Institutes of Health‑funded partnership—draws on single‑cell RNA sequencing, a technique that records the RNA transcripts present in each cell at the moment of sampling. The donors ranged from infants to a 108‑year‑old individual, represented diverse ancestries, and included both neurotypical controls and people diagnosed with one of eight brain disorders: Alzheimer’s disease, dementia with Lewy bodies, Parkinson’s disease, vascular dementia, tauopathy, frontotemporal dementia, schizophrenia or bipolar disorder.
Using this approach, the investigators captured gene‑expression signatures from neurons, immune cells and vascular cells across the dorsolateral prefrontal cortex, the subregion most closely linked to working memory and executive function. Panos Roussos, director of the Center for Disease Neurogenomics at the Icahn School of Medicine at Mount Sinai and a co‑author on all eight related papers, said the study represents the culmination of a massive effort that began in 2019.
Findings on brain development and disease
In a foundational analysis of healthy brains spanning ages less than one to 97, the researchers identified three distinct phases of cortical development. The first phase involves rapid remodelling during early life, followed by a period of relative stability beginning around age 24. A second remodelling phase emerges near age 65, marked by changes in cell types associated with immune activity, stress responses and the brain’s circadian rhythms.
Different cell populations displayed unique patterns of gene activity throughout these stages. Early‑life changes were linked to developmental processes, while late‑life alterations reflected the increasing role of immune‑related and stress‑responsive pathways. These observations provide a framework for interpreting how genetic variation and ageing intersect with disease‑related changes in specific cell types.
Implications for research
“Studying the same region under different conditions enables more consistent comparisons and helps connect our results to existing genetic and molecular studies,” Roussos explained, emphasizing that the prefrontal cortex offers a critical window into brain disease. He added that additional brain regions will be needed to capture the full picture of neurodegeneration.
Computational biologist Zhichao Miao, who was not involved in the work, praised the project’s scale, noting that previous single‑cell brain studies were limited to far fewer individuals. “Pushing us into a population‑scale setting changes the kinds of questions we can ask,” Miao said.
The map is expected to serve as a reference for scientists probing how disease‑associated genetic variants influence cellular function. By linking gene‑activity patterns to specific cell types across the lifespan, the resource may help identify therapeutic targets for Alzheimer’s disease and the other disorders represented in the donor cohort.
Roussos concluded that the dataset opens avenues for future investigations, stating, “This is an important window into brain disease, but additional regions will be needed to understand the full picture.”
Mitchell Landsberg is a Senior Technology Correspondent at News Raise. He covers consumer electronics, artificial intelligence, software developments, and digital privacy trends.
