Melatonin receptors: distribution in mammalian brain and their respective putative functions

• Published in: Brain Structure and Function Vol. 222; no. 7; pp. 2921 - 2939
• Main Authors: Ng, Khuen Yen, Leong, Mun Kit, Liang, Huazheng, Paxinos, George
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.09.2017; Springer Nature B.V
• Subjects: Alzheimer's disease; Anatomy; Animals; Anxiety; Biomedical and Life Sciences; Biomedicine; Brain; Brain - metabolism; Brain architecture; Cell Biology; Central nervous system; Cerebellum; Cerebral cortex; Circadian rhythm; Circadian rhythms; Dorsal raphe nucleus; G protein-coupled receptors; Habenula; Humans; Huntington's disease; Hypothalamus; Mammals; Mammals - anatomy & histology; Melatonin; Melatonin receptors; Mesencephalon; Movement disorders; Neurodegenerative diseases; Neurology; Neurosciences; Pain; Parkinson's disease; Periaqueductal gray area; Pineal gland; Pituitary; Receptors, Melatonin - physiology; Retina; Review; Sleep; Thalamic reticular nucleus; Nociception; Depression; Neurodegenerative disease; Circadian rhythm; Neurogenesis; Melatonin receptor
• ISSN: 1863-2653; 1863-2661; 1863-2661; 0340-2061
• DOI: 10.1007/s00429-017-1439-6

Melatonin, through its different receptors, has pleiotropic functions in mammalian brain. Melatonin is secreted mainly by the pineal gland and exerts its effects via receptor-mediated and non-receptor-mediated actions. With recent advancement in neuroanatomical mapping, we may now understand better the localizations of the two G protein-coupled melatonin receptors MT1 and MT2. The abundance of these melatonin receptors in respective brain regions suggests that receptor-mediated actions of melatonin might play crucial roles in the functions of central nervous system. Hence, this review aims to summarize the distribution of melatonin receptors in the brain and to discuss the putative functions of melatonin in the retina, cerebral cortex, reticular thalamic nucleus, habenula, hypothalamus, pituitary gland, periaqueductal gray, dorsal raphe nucleus, midbrain and cerebellum. Studies on melatonin receptors in the brain are important because cumulative evidence has pointed out that melatonin receptors not only play important physiological roles in sleep, anxiety, pain and circadian rhythm, but might also be involved in the pathogenesis of a number of neurodegenerative diseases including Alzheimer’s disease, Parkinson’s disease and Huntington’s disease.