Endogenous serotonin acts on 5-HT2C-like receptors in key vocal areas of the brain stem to initiate vocalizations in Xenopus laevis.
Endogenous serotonin acts on 5-HT2C-like receptors in key vocal areas of the brain stem to initiate vocalizations in Xenopus laevis.
复制标题
内源性血清素作用于脑干关键发声区域的 5-HT2C 样受体，从而启动非洲爪蟾的发声。
DOI：
10.1152/jn.00827.2009
复制
发表时间：
2010
影响因子：
2.5
通讯作者：
Yamaguchi,Ayako
中科院分区：
文献类型：
--
作者：
Yu,HeatherJ;Yamaguchi,Ayako
5-羟色胺在脊椎动物中启动各种节律行为。以前，我们已经表明，多巴胺能神经元支配的中央发声通路在非洲爪蟾（非洲爪蟾）。我们还发现，外源性5-羟色胺应用于离体大脑在体外激活虚构的发声通过激活5-HT 2C样受体。在这项研究中，我们检查了5-HT 2C样受体的位置，并确定内源性释放的血清素是否也通过激活雄性非洲爪蟾大脑中的5-HT 2C样受体来启动发声。为此，我们首先确定了5-HT 2C样受体的具体位置，使用免疫组织化学。接下来，我们通过将5-HT 2C受体激动剂应用于不同水平横断的脑，研究了表达5-HT 2C样受体的神经元群体中哪些与启动虚构发声功能相关。四个群体的免疫阳性神经元，我们发现，5-HT 2C样受体位于两个地区的脑干发声回路，中缝核和运动核IX-X，启动虚构的发声。我们接下来发现，内源性5-羟色胺也可以通过使用选择性5-羟色胺再摄取抑制剂（SSRI）增加内源性5-羟色胺的细胞外浓度来激活虚构的发声。SSRI诱导的发声起始也是通过激活5-HT 2C样受体介导的，因为阻断这些受体可以防止虚构发声。结果表明，在体内释放的5-羟色胺启动男性发声激活5-HT 2C样受体在脑干发声核。
Serotonin initiates various rhythmic behaviors in vertebrates. Previously we have shown that serotonergic neurons innervate the central vocal pathway in the African clawed frog (Xenopus laevis). We also discovered that exogenous serotonin applied to isolated brains in vitro activates fictive vocalizations by activating 5-HT2C-like receptors. In this study, we examined the location of 5-HT2C-like receptors and determined whether endogenously released serotonin also initiates vocalizations by activating 5-HT2C-like receptors in male Xenopus brains. To this end, we first identified the specific location of 5-HT2C-like receptors using immunohistochemistry. We next examined which of the populations of neurons that express 5-HT2C-like receptors are functionally relevant for initiating fictive vocalizations by applying a 5-HT2Creceptor agonist to brains transected at various levels. Of four populations of immunopositive neurons, we showed that 5-HT2C-like receptors located in two areas of the brain stem vocal circuit, the raphe nucleus and motor nucleus IX-X, initiate fictive vocalizations. We next showed that endogenous serotonin can also activate fictive vocalizations by increasing the extracellular concentration of endogenous serotonin using a selective serotonin reuptake inhibitor (SSRI). The SSRI-induced vocal initiation is also mediated by activation of 5-HT2C-like receptors because blockade of these receptors prevents fictive vocalization. The results suggest that in vivo release of serotonin initiates male vocalizations by activating 5-HT2C-like receptors in the brain stem vocal nuclei.