Brain atlas of 26 million cells maps basal ganglia in unprecedented detail

Researchers have published the most detailed atlas yet of the basal ganglia, profiling nearly 26 million brain cells across humans, macaques, and marmosets. This cross-species reference could help understand conditions from Parkinson's disease to addiction. The atlas, part of the US$500-million BRAIN Initiative Cell Atlas Network, includes 21 million cells from six humans, 3 million from macaques, and 1.5 million from marmosets. Scientists identified 61 conserved cell types across primate species, combining gene expression, DNA modification, and electrical activity data. One study of the striatum found six molecularly distinct zones that become increasingly similar with age, particularly in regions affected by Huntington's and Parkinson's disease. The work spans 26 papers published across multiple Cell Press journals.