A major tenet of the neurosciences has been that all neurons (nerve cells) in the brains of vertebrate animals are formed early in development.
Topic
The discovery of neurogenesis (birth of new neurons) in adult canaries and its implications for neuroscience.
Framework
Old / New
Main Point
Although it was long believed that adult vertebrate brains could not generate new neurons, evidence from studies of canaries shows that adult neurogenesis does occur, which opens new possibilities for understanding and perhaps repairing the human brain. (Most valuable sentence: Final paragraph — )
P1: Traditional View in Neuroscience
For a long time, neuroscientists believed that adult vertebrate brains could not make new neurons; adults were stuck with the neurons they developed early on.
P2: Discovery Through Canary Song
Canaries learn new songs every year, losing and regaining their “vocabulary,” which suggests some sort of ongoing learning and brain change that's more dynamic than previously thought.
P3: Evidence of Neurogenesis in Canaries
Research shows that regions of the brain connected to song learning actually shrink and grow seasonally as the number of neurons decreases after breeding and then new neurons form before the next season. This likely happens because it would be impractical for a flying bird to carry all the neurons needed for a lifetime’s worth of songs.