Human brain has a split origin, new research suggests

Key Points:

• Stanford Medicine researchers have discovered that the human brain consists of two distinct organs—forebrain/midbrain and hindbrain—that evolved independently and originate from separate progenitor cells during embryonic development.
• This finding overturns the long-held belief that the entire brain arises from a single progenitor cell, explaining why scientists have struggled to grow hindbrain neurons in the lab for decades.
• The team successfully grew functional hindbrain motor neurons from human pluripotent stem cells, enabling new research into diseases affecting the brain stem, such as spinal muscular atrophy (SMA) and amyotrophic lateral sclerosis (ALS).
• The study reveals that these two brain regions have fundamentally different chromatin configurations, locking progenitor cells into distinct developmental paths, and shows the pattern is conserved across species dating back over 550 million years.
• This breakthrough opens avenues for better understanding brain stem diseases, developing regenerative therapies, and exploring connections to functions like hunger regulation, which is relevant to obesity treatments.