LIGHT-DARK ENTRAINMENT OF THE GROWTH HORMONE ULTRADIAN RHYTHM IN THE RAT IS MEDIATED BY THE ARCUATE NUCLEUS1,2

Abstract
Monosodium glutamate-induced lesions of the hypothalamic arcuate nucleus cause diminished episodic growth hormone secretion and disrupt light-dark entrainment of the growth hormone rhythm in male rats; such lesions do not affect the light-dark entrainment of the pineal rhythm or of drinking behavior.