Fig. 3
From: The rationale for treating uveal melanoma with adjuvant melatonin: a review of the literature
The anatomy of melatonin secretion. The production and release of melatonin are mainly mediated by postganglionic retinal nerve fibers that exits the eye through the optic nerve, pass through the retinohypothalamic tract to the suprachiasmatic nucleus and then to the pineal gland via the superior cervical ganglion. This axis is activated by darkness and suppressed by light. The circadian rhythm of melatonin secretion is to a lesser extent also controlled by the suprachiasmatic nucleus