Uncovering the Ancient Origins of the Vertebrate 'Fight or Flight' Response
Researchers have debunked a long-held belief that lamprey, a type of jawless fish, lack sympathetic neurons, which are part of the peripheral nervous system. New research led by Marianne Bronner's lab at Caltech has found that sympathetic neurons do exist in lamprey but arise much later in development than previously thought, revising the timeline of sympathetic nervous system evolution. This discovery suggests that the developmental program governing the formation of sympathetic neurons is evolutionarily conserved across all vertebrates, from lamprey to mammals.