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

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 MEL, is much more potent than MEL in converting short-term memory (STM) long-term (LTM) with single administration immediately after the acquisition trial novel object recognition (NOR) task. These data suggest memory-enhancing may be mediated by mechanisms independent activation MT1 and MT2 receptors. In present study, examined contribution receptor-mediated non-receptor-mediated using NOR Mice were administered either AMK, or highly selective MT1/MT2 receptor agonist ramelteon (RAM) varying doses these drugs both STM LTM performance compared. We found AMK RAM facilitating promoting formation. also pretreatment luzindole, antagonist, markedly suppressed only RAM. results acutely enhances through mechanisms.