The human brain takes decades to mature, a prolonged developmental period marked by the constant formation of new connections between brain networks.
However, observing these physical changes in a lab has proven difficult. While artificially grown models of the organ [grown from human stem cells, called human brain organoids, have allowed scientists to study these processes, they’ve been limited to the earliest stages of development — until now.
As detailed in a new paper published in the journal Nature, an international team of scientists have now grown human brain organoids for five full years in a lab. They found that the the biological age of these cultures, as judged by changing genetic markers, perfectly correlated with how much time they “spent in vitro,” allowing them to “record the passage of time over multiple years.”
And if the sound of five-year-old “clumps of brain cells grown in a lab dish,” as New Scientist put it, sounds like something straight out of a horror movie, you’re not alone.
