The ventromedial hypothalamus oxytocin induces locomotor behavior regulated by estrogen
The ventromedial hypothalamus oxytocin induces locomotor behavior regulated by estrogen
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下丘脑腹内侧催产素诱导雌激素调节的运动行为
DOI：
10.1016/j.physbeh.2016.05.047
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发表时间：
2016
期刊：
影响因子：
2.9
通讯作者：
Matsuoka S
中科院分区：
文献类型：
--
作者：
Narita K;Murata T;Matsuoka S
我们之前的研究表明，大鼠下丘脑腹内侧（VMH）神经元的兴奋诱导运动活动。一种催产素受体（Oxtr）存在于下丘脑，并在调节性行为中发挥作用。然而，Oxtr在VMH运动活动中的作用尚不清楚。在这项研究中，我们研究了催产素在VMH中对跑步行为的作用，并研究了雌激素在这种行为改变中的作用。向下丘脑微量注射催产素可引起雄性大鼠跑步行为的剂量依赖性增加。同时注射oxr -拮抗剂、(d(CH2)51、Try(Me)2、Orn8)-催产素可抑制催产素诱导的跑步活动。注射催产素还能诱导去卵巢雌性大鼠的奔跑行为。雌激素预处理OVX大鼠后，催产素诱导的跑步活性增加2倍，VMH中Oxtr mRNA增加3倍。在发情周期中，在发情前的黑暗期，运动活动自发增加。Oxtr mRNA在发情前下午上调。在发情前期黑暗期开始前，拮抗剂阻断催产素神经传递可降低随后的夜间运动活动。这些发现表明，下丘脑下丘脑的Oxtr参与了跑步行为的诱导，而雌激素通过上调Oxtr促进了这一作用，提示催产素参与了雌性大鼠的发情前期运动活动。
Our previous studies demonstrated that excitation of neurons in the rat ventromedial hypothalamus (VMH) induced locomotor activity. An oxytocin receptor (Oxtr) exists in the VMH and plays a role in regulating sexual behavior. However, the role of Oxtr in the VMH in locomotor activity is not clear. In this study we examined the roles of oxytocin in the VMH in running behavior, and also investigated the involvement of estrogen in this behavioral change. Microinjection of oxytocin into the VMH induced a dose-dependent increase in the running behavior in male rats. The oxytocin-induced running activity was inhibited by simultaneous injection of Oxtr-antagonist, (d(CH2)51, Try(Me)2, Orn8)-oxytocin. Oxytocin injection also induced running behavior in ovariectomized (OVX) female rats. Pretreatment of the OVX rats with estrogen augmented the oxytocin-induced running activity twofold, and increased the Oxtr mRNA in the VMH threefold. During the estrus cycle locomotor activity spontaneously increased in the dark period of proestrus. The Oxtr mRNA was up-regulated in the proestrus afternoon. Blockade of oxytocin neurotransmission by its antagonist before the onset of the dark period of proestrus decreased the following nocturnal locomotor activity. These findings demonstrate that Oxtr in the VMH is involved in the induction of running behavior and that estrogen facilitates this effect by means of Oxtr up-regulation, suggesting the involvement of oxytocin in the locomotor activity of proestrus female rats.