Department of Biology, Faculty of Basic Sciences, Islamic Azad University, Ardabil Branch, Ardabil, Iran.
Neurosci Lett. 2012 Oct 24;528(2):93-8. doi: 10.1016/j.neulet.2012.08.074. Epub 2012 Sep 7.
Nicotine, an active tobacco derived alkaloid, regulates the activity of the neuronal nitric oxide synthase (nNOS) as well as the release of nitric oxide (NO) in the nervous system. Nicotinic acetylcholine receptors and nNOS are abundantly co-expressed in the hippocampal neurons and are found to alter anxiety-like behaviors in rodents. Dorsal hippocampus may be a site for modulation of anxiety. Therefore, in this study, we investigated the possible interactions between nicotine and NO systems of the dorsal hippocampus and the resultant effect on anxiety-like behaviors. The elevated plus-maze (EPM) test has been used to test the anxiety. Intraperitoneal administration of nicotine (0.5mg/kg) decreased the open arm time percentage (%OAT) and open arm entries percentage (%OAE) but not the locomotor activity, indicating an anxiogenic-like response. Intra-CA1 injection of l-arginine (a NO precursor) or l-NAME (a NOS inhibitor) also caused anxiogenic-like effects. On the other hand, injection of the low dose nicotine before different doses of l-arginine or l-NAME blocked the anxiogenic-like response induced by the drugs. Our results suggested that, both NO and nicotinic cholinergic systems not only play a part in the modulation of the anxiety in mice dorsal hippocampus, but also demonstrate a complex interaction in this respect.
尼古丁是一种烟草衍生的活性生物碱，它调节神经元型一氧化氮合酶（nNOS）的活性以及神经系统中一氧化氮（NO）的释放。烟碱型乙酰胆碱受体和 nNOS 在海马神经元中大量共表达，并被发现改变啮齿动物的焦虑样行为。背侧海马可能是调节焦虑的部位。因此，在这项研究中，我们研究了背侧海马中的尼古丁和 NO 系统之间可能的相互作用，以及它们对焦虑样行为的影响。高架十字迷宫（EPM）测试已用于测试焦虑。腹腔内给予尼古丁（0.5mg/kg）可降低开放臂时间百分比（%OAT）和开放臂进入百分比（%OAE），但不影响运动活性，表明有焦虑样反应。CA1 内注射 l-精氨酸（NO 前体）或 l-NAME（NOS 抑制剂）也会引起焦虑样效应。另一方面，在不同剂量的 l-精氨酸或 l-NAME 之前注射低剂量的尼古丁可阻断药物引起的焦虑样反应。我们的结果表明，NO 和烟碱型胆碱能系统不仅在调节小鼠背侧海马的焦虑中发挥作用，而且在这方面还表现出复杂的相互作用。
