Our brains are protected by an invisible fortress wall, keeping it safe from many dangers. Unfortunately, it also keeps out a lot of the drugs that could help cure diseases of the brain. In this month’s column for Discover, I look at some of the newest strategies for scaling the wall. Check it out.

Image: Ken Lund, Flickr, via Creative Commons

Originally published November 16, 2011. Copyright 2011 Carl Zimmer.