Deep in a lab in Cambridge, England, you will find see an extraordinary thing: tiny, exact replicas of the human brain growing in a petri dish.
Their creator, Madeline Lancaster, still remembers the day she first wanted to study the human brain as a small girl. Her father was a scientist, and one day he allowed her to peer down a microscope and view a neuron growing in a petri dish. “I was completely struck by how beautiful and how complex the neural structure is. It’s just amazing.”
The brain contains more than 100 billion of these brain cells (that’s the same as the number of stars in our galaxy) each with thousands of synapses connecting it to other areas of the brain. Little wonder that many, including Lancaster, believe it to be the most complicated object in the Universe.
Unfortunately, it’s been enormously difficult to probe its secrets – it’s not as if a scientist can just lift off the skull, like the hood of a car, and peer inside at the tissue underneath. And animal studies can only tell us so much about our own minds.
It is for this reason that Lancaster has been trying to build her own, miniature version of the human brain, allowing her to probe its structure and development in more detail. She uses stem cells cultivated from skin samples and then bathes them in nutrients and vitamins designed to trigger their development into neurons, before planting them in a dense protein gel. Amazingly, as the cells replicate and grow, they start to organise themselves into a tiny model of our own brains.