The caudate nucleus is well developed in rats, mice, and chess masters

 Chess masters use different parts of the brain than the rest of us: story here (Bloomberg) and here (MSNBC)

General conclusion: "Expertise is the result of long, serious training."  If you're interested in the subject (or if you want interesting reads with many thoughts applicable to many things beyond chess), I again recommend Gladwell's Outliers and Lehrer's How We Decide.