Abstract
The mammalian pineal gland is a neuroendocrine organ regulated by environmental photoperiod. The main innervation of the pineal gland that regulates melatonin synthesis consists of fibers from the sympathetic superior cervical ganglion (Kappers, 1960; Reuss, 1999) which, by releasing noradrenaline (Wurtman et al, 1967; Drijfhout et al., 1996), activates receptors ±1 and b1 adrenergic resu…