Roger Guillemin, born in 1924 in Dijon, France, is one of the founders of the field of neuroendocrinology. Studying sheep brains, taken from slaughterhouses, he successfully proved that the hypothalamus releases hormones that regulate the pituitary gland. He was awarded the 1977 Nobel Prize for Physiology or Medicine. He also discovered the class of pleasure-related proteins called endorphins. He has served as a professor at the Baylor College of Medicine and the Salk Institute for Biological Studies.