Melatonin Enhances Object Recognition Memory through Melatonin MT1 and MT2 Receptor-Mediated and Non-Receptor-Mediated Mechanisms in Male Mice

作     者：Masahiro Sano Hikaru Iwashita Atsuhiko Hattori Atsuhiko Chiba Masahiro Sano;Hikaru Iwashita;Atsuhiko Hattori;Atsuhiko Chiba

作者机构：Department of Materials and Life Sciences Faculty of Science and Technology Sophia University Tokyo Japan Department of Biology College of Liberal Arts and Sciences Tokyo Medical and Dental University Chiba Japan 

出 版 物：《Journal of Behavioral and Brain Science》 (行为与脑科学期刊（英文）)

年 卷 期：2022年第12卷第12期

页      面：640-657页

学科分类：1007[医学-药学(可授医学、理学学位)] 1006[医学-中西医结合] 100706[医学-药理学] 100602[医学-中西医结合临床] 10[医学] 

主　　题：Melatonin N1-Acetyl-5-Methoxykynuramine Ramelteon Novel Object Recognition Memory Melatonin Receptors 

摘      要：Melatonin (MEL) has been reported to have acute enhancing effects on some aspects of cognition. Recently, we revealed that N1-acetyl-5-methoxyquinuramine (AMK), a brain metabolite of MEL, is much more potent than MEL in converting short-term memory (STM) to long-term memory (LTM) with a single administration immediately after the acquisition trial of the novel object recognition (NOR) task. These data suggest that the memory-enhancing effects of MEL may be mediated by mechanisms independent of the activation of MEL MT1 and MT2 receptors. In the present study, we examined the contribution of MT1 and MT2 receptor-mediated and non-receptor-mediated mechanisms to the acute memory-enhancing effects of MEL using NOR task. Mice were administered with either MEL, AMK, or a highly selective MT1/MT2 receptor agonist ramelteon (RAM) immediately after the acquisition trial and the effects of varying doses of these drugs on both STM and LTM performance were compared. We found that both AMK and RAM were more potent than MEL in both facilitating STM and promoting LTM formation. We also found that pretreatment with luzindole, a MT1/MT2 receptor antagonist, markedly suppressed only the effects of RAM. These results suggest that acutely administered MEL enhances NOR memory through both MT1 and MT2 receptor-mediated and non-receptor-mediated mechanisms.