Davidson, director of the Center for Investigating Healthy Minds at the University of Wisconsin, says he is exploring whether activating the frowning muscle between the eyebrows, known as the corrugator, is associated with activity in the amygdala, the part of the brain that processes emotions such as fear.

WSJ: Stress-Busting Smiles

Michael Davidson, a heart specialist at Rush University Medical Center in Chicago and a tester of the combo pill, predicts "a brutal three-way war" for market share among Vytorin, Lipitor and AstraZeneca's Crestor.

FORBES: Pills and Poker

Mr. DAVIDSON: Well, right now, Lambda Legal, the National Center for Lesbian Rights and the ACLU have filed a lawsuit directly with the California Supreme Court to invalidate Proposition 8.

NPR: California Gay Leaders Assess Marriage Defeat