The human brain holds a mind-boggling 100 billion neurons. And each of those cells makes anywhere from 1,000 to 10,000 connections to other neurons.Imagine, then, the painstaking task of mapping out this complicated wiring diagram. That's the lofty goal of the Human Connectome Project, a $30 million scheme sponsored by the National Institutes of Health. The agency is reviewing proposals and expects to start funding them by July.Ever since the famous lesion studies of the 19th century, we've learned a lot about the 100 or so distinct regions of the brain, from the spot above the ear that allows us to speak to the area in the back of the head that activates when our eyes see light. But scientists say the real challenge is to understand how these regions connect.Read more at...SFARI, April 2010.