Institute of Physiology, University of Pécs, Medical School, Pécs, Hungary; Neuroscience Center, University of Pécs, Pécs, Hungary.
Institute of Physiology, University of Pécs, Medical School, Pécs, Hungary; Neuroscience Center, University of Pécs, Pécs, Hungary.
Horm Behav. 2020 Aug;124:104777. doi: 10.1016/j.yhbeh.2020.104777. Epub 2020 May 24.
Neuropeptide oxytocin (OT) is involved in the regulation of social and non-social behaviour. The central nucleus of amygdala (CeA), part of the limbic system, plays an important role in learning, memory, anxiety and reinforcing mechanisms. CeA has been shown to be rich in OT receptors in rodents. Our previous findings indicated that OT in the rat CeA has a dose dependent rewarding and anxiolytic effect. The aim of our present study was to examine in the CeA the possible interaction of OT and D2 dopamine (DA) receptor antagonist Sulpiride on reinforcement in place preference test and on anxiety in elevated plus maze test. Wistar rats were microinjected bilaterally with 10 ng OT. In different group of animals 4 μg D2 DA receptor antagonist was applied. Other animals received D2 DA receptor antagonist 15 min before 10 ng OT treatment or vehicle solution into the CeA. Rats receiving 10 ng OT spent significantly longer time in the treatment quadrant during the test session in conditioned place preference test. Prior treatment with D2 DA receptor antagonist blocked the rewarding effects of OT. Antagonist in itself did not influence the time rats spent in the treatment quadrant. In elevated plus maze test, rats receiving 10 ng OT spent significantly longer time on the open arms. Prior treatment with D2 DA receptor antagonist blocked the effects of OT. Our results show that DA system plays a role in positive reinforcing and anxiolytic effects of OT because D2 DA receptor antagonist can block these actions.
神经肽催产素（OT）参与社会和非社会行为的调节。杏仁中央核（CeA），边缘系统的一部分，在学习、记忆、焦虑和强化机制中起着重要作用。在啮齿动物中，CeA 被证明富含 OT 受体。我们之前的研究结果表明，大鼠 CeA 中的 OT 具有剂量依赖性的奖赏和抗焦虑作用。本研究的目的是在 CeA 中研究 OT 和 D2 多巴胺（DA）受体拮抗剂 Sulpiride 对强化（位置偏好测试）和焦虑（高架十字迷宫测试）的可能相互作用。Wistar 大鼠双侧脑室内注射 10ng OT。在不同的动物组中，应用 4μg D2 DA 受体拮抗剂。其他动物在接受 10ng OT 治疗或载体溶液之前 15 分钟接受 D2 DA 受体拮抗剂。在条件性位置偏好测试中，接受 10ng OT 的大鼠在测试期间在治疗象限中花费的时间明显更长。D2 DA 受体拮抗剂的预先处理阻断了 OT 的奖赏作用。拮抗剂本身并不影响大鼠在治疗象限中花费的时间。在高架十字迷宫测试中，接受 10ng OT 的大鼠在开放臂上花费的时间明显更长。D2 DA 受体拮抗剂的预先处理阻断了 OT 的作用。我们的结果表明，DA 系统在 OT 的正强化和抗焦虑作用中起作用，因为 D2 DA 受体拮抗剂可以阻断这些作用。
