Brane is a mathematical term for surface. Which is interesting because the reason our brains fold and wrinkle the way they do is because all of the work a brain does happens on the surface. And the only way to increase surface area and still fit into a skull is to start folding.
Alternatively, in a zombie apocalypse, they (the zombies) stagger about and moan "brrraaaaiiins". I am kind of a zombie at the moment, but I am still amused at the confluence of branes and brains.