A new type of progenitor cell found deep in the developing human brain spawns a steady supply of inhibitory interneurons and glia, according to a new study. Compared with other mammals, humans and other primates have larger populations—and a greater diversity—of inhibitory interneurons. In mice, most interneurons are born in a brain structure called the medial ganglionic eminence and later migrate to the cortex. ” The study is a ‘tour de force’ and ‘adds an important mechanistic piece’ to understanding human interneuron diversity. U sing spatial transcriptomics in human fetal brain tissue from different stages of development revealed seven molecularly distinct clusters of progenitor cells.