Since humans split from their primate ancestors, their brains evolved with a larger mass relative to body weight, more cortical neurons, and distinct connectivity patterns. Human neurons mature more slowly, a trait known as neoteny, likely influencing these differences. Gene regulation, not new genes, may underlie species differences, particularly in the primate lineage. The role of these regulatory mechanisms in human neuron development remains poorly understood. This lecture explores the molecular factors affecting prolonged human neuron maturation and its implications for human development and neurodevelopmental diseases. (#39270)