Julius Axelrod (May 30, 1912 – December 29, 2004) was an American biochemist. He won a share of the Nobel Prize in Physiology or Medicine in 1970 along with Bernard Katz and Ulf von Euler. The Nobel Committee honored him for his work on the release and reuptake of catecholamine neurotransmitters, a class of chemicals in the brain that include epinephrine, norepinephrine, and, as was later discovered, dopamine. Axelrod also made major contributions to the understanding of the pineal gland and how it is regulated during the sleep-wake cycle.