Semeniken K, Merchenthaler I, Hu W, Dudas B
Neuroendocrine Organization Laboratory (NEO), Lake Erie College of Osteopathic Medicine, Erie, PA, United States.
J Chem Neuroanat. 2009 Jul;37(4):229-33. doi: 10.1016/j.jchemneu.2009.01.004. Epub 2009 Feb 7.
Previous studies revealed that oxytocin release is increased by various forms of stress. Hypertonic saline injection, immobilization, and several other stressors elevated the blood level of oxytocin in rats. However, the mechanism of the stress-induced oxytocin release in human is not elucidated yet. Although numerous studies indicate that catecholamines play a pivotal role in modulating the release of oxytocin, there is a lack of data regarding the morphological substrate of this phenomenon. In order to reveal putative juxtapositions between tyrosine hydroxylase-immunoreactive (TH-IR) catecholaminergic and the oxytocinergic systems in the human hypothalamus, we utilized double-label immunohistochemistry in the present study. Numerous TH-IR axon varicosities abutted on oxytocin-IR neurons in the supraoptic and paraventricular nuclei, forming synapse-like associations. Close examination of these juxtapositions with high magnification failed to reveal any gaps between the contacting elements. In summary, the intimate associations between the TH-IR and oxytocin-IR elements may be functional synapses and may represent the morphological substrate of stress-influenced oxytocin release. The finding that several oxytocin-IR perikarya did not receive apparent TH innervation suggests that additional mechanisms may play significant roles in the oxytocin modulation by stressors.
先前的研究表明，各种形式的应激会增加催产素的释放。高渗盐水注射、固定以及其他几种应激源会提高大鼠血液中催产素的水平。然而，应激诱导人类催产素释放的机制尚未阐明。尽管大量研究表明儿茶酚胺在调节催产素释放中起关键作用，但关于这一现象的形态学基础的数据却很缺乏。为了揭示人类下丘脑酪氨酸羟化酶免疫反应性（TH-IR）儿茶酚胺能系统与催产素能系统之间可能存在的并置关系，我们在本研究中采用了双标记免疫组织化学方法。在视上核和室旁核中，大量TH-IR轴突膨体与催产素-IR神经元相邻，形成类似突触的联系。用高倍镜仔细检查这些并置关系时，未发现接触元件之间有任何间隙。总之，TH-IR与催产素-IR元件之间的紧密联系可能是功能性突触，可能代表了应激影响催产素释放的形态学基础。几个催产素-IR胞体未接受明显的TH神经支配这一发现表明，其他机制可能在应激源对催产素的调节中起重要作用。
