For more than six decades, neuroscientists have wrestled with a fundamental question about the human brain: Do adults continue to make new neurons, or are we born with all the brain cells we’ll ever have?

Scientists discovered that the brain keeps making new neurons even in adulthood, offering hope for brain health treatments.

In the hippocampus, a critical brain region for learning and memory, new cells emerge in some people into late adulthood, according to a study published July 3 in the journal Science. The findings tip the scales in a still-active debate over how our brains continue to develop throughout life.