This Weird Rainbow Nipple is Actually a Sophisticated Model of a Brain

There are lots of thing I can think of when I see this gelatinous rainbow mass, but I do not think "brain." Yet this funny-looking thing is one of the most complex models scientists have ever developed to study what traumatic injury does to brain cells.

Growing brain cells in a petri dish is not terribly hard, but cells tend to grow in a simple two dimensional layer. Real brains, of course, are made of complex 3D structures, with multiple organized layers of neurons. To coax rat brain cells into growing in 3D—and to begin to replicate a real brain—scientists at Tufts created this rainbow bullseye structure.

Each colored doughnut is punched out of a protein-rich scaffold made from silk protein filled with collagen gel inside. The scaffold is seeded with rat neurons that send their growing axons through the gel. The insides of each doughnut, filled with axons, are like the white matter of the brain, and the nuclei of the neurons on the edges make up the gray matter. When several concentric doughnut are assembled, they resemble the layers of neurons in brain.

So it (very abstractly) looks like a brain, but does it act like brain? When the scientists recorded the electrical and chemical activity of these brain-like structures as they dropped weights on them, the response of the individual neurons was similar to those in real brains. The cells can grow like this for a few months, suggesting this could be model for studying how brains react to trauma.

Ultimately, this tells us something about the state of modern neuroscience. We're so far away from understanding how all the structures of a brain work that we can only make simplified and abstracted versions of it. Jelly doughnuts full of brain cells are about the best we can currently do. But they're still impressive in their own right. [PNAS via NBC News]

Images: Tufts University