Objective: To investigate the mechanism of circadian rhythm of skin and core temperature as regulated by pineal and suprachiasmatic nucleus (SCN) in rats.
Method: Pineal destruction and melatonin interference test were employed.
Result: The two nuclei functioned differently in the maintenance of the temperature rhythm. Changes of the temperature level were nucleus related, i.e., up-regulated by pineal and down-regulated by SCN. In terms of initiation and daily running of the rhythmic oscillation, pineal is probably the central clock of the skin temperature rhythm, while SCN mainly controls the core temperature rhythm.
Conclusion: The two nuclei interlink by way of neuroendocrine signals to balance over the oscillatory system of the circadian temperature.