Neurons expressing relaxin 3/INSL 7 in the nucleus incertus respond to stress
Neurons expressing relaxin 3/INSL 7 in the nucleus incertus respond to stress
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DOI：
10.1111/j.1460-9568.2005.03980.x
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发表时间：
2005-03-01
影响因子：
3.4
通讯作者：
Ibata, Y
中科院分区：
文献类型：
--
作者：
Tanaka, M;Iijima, N;Ibata, Y
Relaxin 3/INSL 7最近被鉴定为胰岛素/松弛素超家族的新成员。虽然有报道称其主要在脑中表达，但其在中枢神经系统中的详细分布和功能仍不清楚。在本研究中，我们证明，在大鼠松弛素3主要表达在正中背盖脑桥的未定核（NI）的神经元。其他松弛素3表达神经元散在分布于脑桥中缝核、中脑导水管周围灰质和中脑网状结构的黑质背侧区。松弛素3免疫反应阳性纤维投射特别密集的隔，海马，外侧下丘脑和膝状体间叶的丘脑。超微结构检查显示，松弛素3定位于核周的致密核心囊泡，也观察到在轴突的突触终末。由于几乎所有的松弛素3含有神经元表达促肾上腺皮质激素释放因子（CRF）1型受体在NI，我们研究了松弛素3神经元的反应，脑室内管理的CRF; 65%的松弛素3神经元表达c-Fos 2小时后，脑室内管理1微克CRF。结果表明，水束缚应激后，NI中60%的松弛素3神经元表达c-Fos，松弛素3 mRNA表达显著增加。总的来说，这些结果表明，松弛素3产生的NI是从神经末梢释放，并参与调节应激反应。
Relaxin 3/INSL 7 has recently been identified as a new member of the insulin/relaxin superfamily. Although it was reported to be dominantly expressed in the brain, its detailed distribution and function in the central nervous system are still obscure. In the present study we demonstrated that in the rat relaxin 3 was mainly expressed in neurons of the nucleus incertus (NI) of the median dorsal tegmental pons. Other relaxin 3-expressing neurons were scattered in the pontine raphe nucleus, the periaqueductal gray and dorsal area to the substantia nigra in the midbrain reticular formation. Relaxin 3-immunoreactive fibers projected particularly densely in the septum, hippocampus, lateral hypothalamus and intergeniculate leaflet of the thalamus. Ultrastructural examination revealed that relaxin 3 was localized in the dense-cored vesicles in the perikarya and was also observed in the synaptic terminals of axons. As almost all relaxin 3-containing neurons express corticotropin-releasing factor (CRF) type 1 receptor in the NI, we examined the response of relaxin 3 neurons to intracerebroventricular administration of CRF; 65% of relaxin 3 neurons expressed c-Fos 2 h after intracerebroventricular administration of 1 mu g CRF. We then confirmed that c-Fos was induced in 60% of relaxin 3 neurons in the NI and the expression of relaxin 3 mRNA increased significantly in the NI after water-restraint stress. Collectively, these results suggest that relaxin 3 produced in the NI is released from nerve endings and is involved in the regulation of the stress response.