title: Chronic treatment with melatonin stimulates dendrite maturation and complexity in adult hippocampal neurogenesis of mice.
abstract: In the course of adult hippocampal neurogenesis, the postmitotic maturation and survival phase is associated with dendrite maturation. Melatonin modulates the survival of new neurons with relative specificity. During this phase, the new neurons express microtubule-associated protein doublecortin (DCX). Here, we show that the entire population of cells expressing DCX is increased after 14 days of treatment with melatonin. As melatonin also affects microtubule polymerization which is important for neuritogenesis and dendritogenesis, we studied the consequences of chronic melatonin administration on dendrite maturation of DCX-positive cells. Treatment with melatonin increased the number of DCX-positive immature neurons with more complex dendrites. Sholl analysis revealed that melatonin treatment lead to greater complexity of the dendritic tree. In addition, melatonin increased the total volume of the granular cell layer. Besides its survival-promoting effect, melatonin thus also increases dendritic maturation in adult neurogenesis. This might open the opportunity of using melatonin as an adjuvant in attempts to extrinsically stimulate adult hippocampal neurogenesis in neuropsychiatric disease, dementia or cognitive ageing.
authors.affiliation: Laboratory of Neurogenesis, Department of Neuropharmacology, National Institute of Psychiatry. Mexico DF, Mexico.
authors.forename: Gerardo
authors.initials: G
authors.lastname: Ramirez-Rodriguez
authors.forename: Leonardo
authors.initials: L
authors.lastname: Ortíz-López
authors.forename: Aline
authors.initials: A
authors.lastname: Domínguez-Alonso
authors.forename: Gloria A
authors.initials: GA
authors.lastname: Benítez-King
authors.forename: Gerd
authors.initials: G
authors.lastname: Kempermann
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D003712:Dendrites / Q000187:drug effects*; D018891:Dentate Gyrus / Q000166:cytology / Q000187:drug effects; D000089622:Doublecortin Domain Proteins; D000089662:Doublecortin Protein; D006624:Hippocampus / Q000166:cytology* / Q000187:drug effects*; D007150:Immunohistochemistry; D008550:Melatonin / Q000494:pharmacology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D008870:Microtubules / Q000378:metabolism; D055495:Neurogenesis / Q000187:drug effects*; D009474:Neurons / Q000166:cytology* / Q000187:drug effects*; D009479:Neuropeptides / Q000378:metabolism
chemical_list: D000975:Antioxidants; C000714847:Dcx protein, mouse; D000089622:Doublecortin Domain Proteins; D000089662:Doublecortin Protein; D008869:Microtubule-Associated Proteins; D009479:Neuropeptides; D008550:Melatonin