Circadian Rhythm of Serotonin in the Pineal Body of Immunosympathectomized Immature Rats

Abstract
In the pineal body of the immature rat the circadian rhythm of serotonin persists when sympathetic innervation is abolished by the administration of nerve growth factor antiserum. This rhythm is regulated by a mechanism that does not involve the sympathetic innervation and is, therefore, fundamentally different from that in the adult.