Recreating a brain is hard. The human brain has about 100 billion neurons, and while we're working on mapping the connections between them in the Human Connectome Project, we're still some way off.
So far, the biggest brain we've fully simulated is a 1mm-long flatworm with just 302 neurons. But now we're getting closer to something larger with an announcement that the Blue Brain Project has managed to digitally recreate a section of a teenage rat brain comprising of 31,000 neurons.
A team lead by Henry Markram took a slice of a rat's neocortex - an area that's pretty different from brain to brain, and painstakingly reconstructed it in a computer model. Once complete, they used supercomputers to simulate the behaviour of neurons in different conditions.
Stuck In The Wrong State
"The reconstruction required an enormous number of experiments," said Markram. "It paves the way for predicting the location, numbers, and even the amount of ion currents flowing through all 40 million synapses."
He added: "An analogy would be a computer processor that can reconfigure to focus on certain tasks. The experiments suggest the existence of a spectrum of states, so this raises new types of questions, such as 'what if you're stuck in the wrong state?'"
As well as being a step on the road to artificial intelligence, the simulation could allow for new discoveries in the behaviour of rats and other animals. The details were described in the journal Cell.
Image credit: MAKRAM ET AL./CELL 2015