The human brain is made up of billions of cells. We do not know the identity or exact function of countless thousands of them since comprehensive efforts to catalogue neurons have just recently begun. Studying these many still unidentified cells is an important “hot-spot” in frontier brain research since it offers the discovery of new cell functions that could play important roles in many diseases. Scientists have now described many previously unknown neurons in the hypothalamus and determined the function of a hitherto uncharted dopamine cell.