Science · 1970 · 44 citations · 9 references
Life SciencesNeurosciencePhysiologyCircadian RhythmsNeurochemistryNeuroendocrinologyCircadian EndocrinologyCircadian Molecular MechanismsCircadian PhysiologyLight PerceptionPhotoperiodic EndocrinologyPhotoreceptor PhysiologyCircadian Lighting EffectsCircadian Neurochemical RegulationCircadian PhotobiologyLight-dark Cycle ResponsesLight-mediated Hormonal RegulationPineal Gland AnatomyPineal Gland FunctionPineal Gland Physiology
A circadian rhythm has been found in hydroxyindole-O-methyltransferase activity of the pineal gland of blinded 12-day-old rats. Five additional hours of lighting can partly prevent the nocturnal increase in pineal hydroxyindole-O-methyltransferase activity in such rats. Removal of the Harderian gland abolishes this response to light in 12-day-old blinded animals, giving further support to the suggestion that this gland may function as an extraretinal photosensitive organ influencing the pineal gland in blinded suckling rats.
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