Evidence for Suprachiasmatic Vasopressin Neurones Innervating Kisspeptin Neurones in the Rostral Periventricular Area of the Mouse Brain: Regulation by Oestrogen
Evidence for Suprachiasmatic Vasopressin Neurones Innervating Kisspeptin Neurones in the Rostral Periventricular Area of the Mouse Brain: Regulation by Oestrogen
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DOI：
10.1111/j.1365-2826.2010.02045.x
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发表时间：
2010-09-01
影响因子：
3.2
通讯作者：
Kallo, I.
中科院分区：
文献类型：
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作者：
Vida, B.;Deli, L.;Kallo, I.
在啮齿类动物中，来自视交叉上核 (SCN) 的昼夜节律信号对于促性腺激素释放激素 (GnRH) 的促发情激增至关重要，而促性腺激素释放激素 (GnRH) 反过来又会诱导黄体生成素 (LH) 激增和排卵。我们假设前腹侧脑室周围和脑室周围视前核 (AVPV/PeN) 中的 Kisspeptin (KP) 神经元构成 SCN 和 GnRH 神经元之间通讯通路的一部分。在顺行轨迹追踪研究中，我们首先鉴定了 SCN 起源的含加压素 (VP) 轴突，与 KP 免疫反应性 (IR) 神经元并置。量化这种输入的研究依赖于这样的观察：SCN 中的 VP 合成神经元与其他 VP 系统的不同之处在于它们缺乏甘丙肽表达。在卵巢切除小鼠中，AVPV/PeN 内 30.79 +/- 1.63% 的 KP-IR 核周和近端树突出现甘丙肽阴性 VP-IR 静脉曲张。雌激素治疗显着增加了 KP-IR 神经元的数量，其百分比由甘丙肽阴性 VP-IR 静脉曲张 (46.95 +/- 1.88%) 和单个 KP-IR 神经元上的 VP-IR 并置数量决定。在超微结构水平上，VP-IR末端与KP-IR神经元形成对称突触，这与SCN神经元建立的抑制性突触的形态一致。与 VP 相比，由 SCN 神经元的独特子集合成的血管活性肠多肽 (VIP) 在与 KP-IR 神经元相邻的轴突中很少出现。总而言之，我们的结果与以下假设一致：位于小鼠 AVPV/PeN 中的 KP 神经元通过血管加压素单突触途径接收来自 SCN 的昼夜节律信息，该途径由雌激素增强。
In rodents, a circadian signal from the suprachiasmatic nucleus (SCN) is essential for the pro-oestrous surge of gonadotrophin-releasing hormone (GnRH), which, in turn, induces luteinising hormone (LH) surge and ovulation. We hypothesised that kisspeptin (KP) neurones in the anteroventral periventricular and periventricular preoptic nuclei (AVPV/PeN) form part of the communication pathway between the SCN and GnRH neurones. In anterograde track tracing studies, we first identified vasopressin (VP)-containing axons of SCN origin in apposition to KP-immunoreactive (IR) neurones. Studies to quantify this input relied on the observation that VP-synthesising neurones in the SCN differ from other VP systems in their lack of galanin expression. In ovariectomised mice, 30.79 +/- 1.63% of KP-IR perikarya and proximal dendrites within the AVPV/PeN received galanin-negative VP-IR varicosities. Oestrogen-treatment significantly increased the number of KP-IR neurones, with their percentage apposed by galanin-negative VP-IR varicosities (46.95 +/- 1.88%) and the number of VP-IR appositions on individual KP-IR neurones. At the ultrastructural level, the VP-IR terminals formed symmetric synapses with KP-IR neurones, which was in accordance with the morphology of inhibitory synapses established by SCN neurones. By contrast to VP, vasoactive intestinal polypeptide (VIP), which is synthesised by a distinct subset of SCN neurones, occurred only rarely in axons apposed to KP-IR neurones. Altogether, our results are consistent with the hypothesis that KP neurones located in the mouse AVPV/PeN receive circadian information from the SCN via a vasopressinergic monosynaptic pathway, which is enhanced by oestrogen.