Over 100 million people worldwide suffer from severe sleep problems, which have major repercussions on the onset of a variety of pathologies including obesity, diabetes, and dementia to name a few. The major sleep hormone in the body is melatonin which is produced by the pineal gland. The major function of the pineal gland is to convey the light inputs received from the retina into a language understandable to the rest of the body. This is achieved through the synthesis and release of melatonin on a light and dark cycle according to the inputs from the retina and controlled by adrenergic receptors. The most impressive and mysterious aspect of the system is the rapid ability of melatonin to be produced and or degraded as the cycle changes. We have shown that part of this rapid response is due to the formation of receptor-receptor complexes (heteromers) between the adrenergic receptors α1B or β1 and the D4 dopamine receptor. We are now characterizing the mechanistic details behind this heteromer and how the complex is regulated.