Rat Brain Has a Micro-Topographic Map of Rat's Whiskers.

Mark Andermann and Christopher Moore of the McGovern Institute for Brain Research at MIT discovered an "exquisite micro-map of the brain. It's the size of the period at the end of this sentence, and it's in a most unexpected place -- connected to the whiskers on a rat's face."

The layout of whiskers on a rat's face creates a topographic map, with one-to-one correspondence between a whisker and a "barrel" of approximately 4,000 densely packed neurons. Like the grid coordinates in the game Battleship, stimulating one whisker barrel, say the third one in from row D, or D3, tells the brain exactly what's happening at that location.

Link (via Scribal Terror)