Neuroscientists at Cold Spring Harbor Laboratory have just publicly released the first batch of gigapixel images showing how the neuronal pathways in mice are all connected to each other. It's the first step towards the first ever wiring diagram of an entire vertebrate brain.
For being the source of all knowledge, creativity, consciousness, and everything else that defines our existence, we're still pretty clueless about our brains. This is because our brains are unfathomably complex. Or at least, we haven't yet been able to fathom them, and at this point, we're not even entirely sure how they're wired together.
The Mouse Brain Architecture Project is tackling this problem by creating a map of an entire mouse brain at the microscopic scale, which has never been done before. People have mapped entire brains at low resolution with MRI, and they've mapped little bits brains at very high resolution with electron microscopes, but using an optical microscope provides a realistic way of making a detailed map of an entire brain (a mouse brain, at least) all at once.
Part of the advantage of making maps at the microscopic scale is that the nerves that run through the brain are all visible, and more importantly, traceable. The researchers divvied up a series of mouse brains (from mice of the same sex and age) into 250 equidistant, pre-defined grid points, and at each grid point, they injected four different kinds of tracers and then took microscopic photos of how the nerves lit up. The final data set (today's release is just the first taste) will take all of this tracer data and weave it together into a comprehensive wiring diagram of the mouse brain.
As any zombie will tell you, mice brains are not the same as human brains, but mice are also some of the most heavily researched animals on the planet. The idea here is that learning more about how mouse brains work will help provide insights into how and why our own brains do what they do.