In Schwartz's and Gainer's study of suprachiasmatic nucleus glucose consumption, the suprachiasmatic nucleus was found to have higher glucose consumption during the daytime than during the night. This rhythm of activation was present both with and without environmental light exposure, providing the first evidence for the suprachiasmatic nucleus as an endogenous circadian clock. This research was pivotal in confirming circadian rhythm regulation by the suprachiasmatic nucleus, and aided new techniques to study neural mechanisms.
