Since the 1970’s, scientists have been unable to determine which cells in the brain are responsible for controlling the circadian rhythm in humans, due to the massive number of neurons involved. The circadian rhythm in humans, which is produced by the SCN (suprachiasmatic nucleus), is located within the hypothalamus. Approximately 2 years ago, Dr. Joseph Takahashi (Chairman of Neuroscience at UT Southwestern) discovered that a group of the SCN neurons express a neuropeptide called NMS (neuromedin S), which is necessary for the control of the circadian rhythm in humans. These NMS neurons perform as a regulator for the body’s sleep cycle, much like a pacemaker works with the heart. This study was a gateway into future treatments related to sleep disorders, depression, Alzheimer’s disease, metabolic dysfunctions and other neurological problems. Dr. Takahashi’s lab continues to make great strides in regards to this research. Click here to read about the study on cells affecting the circadian rhythm in humans from UT Southwestern Medical Center.