Horrifying. Awe-inspiring. Beyond imagination. Scientists are running out of superlatives to describe the complexity of the brain’s billions of brain cells and estimated 100 trillion connections. And it gets more daunting every time their view of the brain gets more detailed. Without seeing the brain’s wiring on a synaptic level, some neuroscientists believe we’ll never truly understand how it works. Others worry that a flood of data will drown the field. Now, a new video showing the nanoscale connections within a tiny chunk of mouse cortex shows what neuroscientists are up against. Using a technology called VAST, which can automatically label individual neurons, glia, and blood vessels different colors, as well as smaller structures such as dendrites and mitochondria, the researchers analyzed the contents of three cylindrical chunks of brain tissue, each no bigger than grains of salt. Among other structures, they created an annotated inventory of 1700 synapses, the team reports online today in Cell.

(Video credit: Science)