Catecholaminergic Fiber Innervation of the Vocal Motor System Is Intrasexually Dimorphic in a Teleost with Alternative Reproductive Tactics.
Catecholaminergic Fiber Innervation of the Vocal Motor System Is Intrasexually Dimorphic in a Teleost with Alternative Reproductive Tactics.
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DOI：
10.1159/000438720
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Forlano PM
中科院分区：
文献类型：
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作者：
Ghahramani ZN;Timothy M;Kaur G;Gorbonosov M;Chernenko A;Forlano PM
包括神经递质多巴胺和去甲肾上腺素在内的儿茶酚胺是脊椎动物感觉运动功能、生殖和性动机行为（包括声音-声学通信）的已知调节剂。最近，我们证明了强大的儿茶酚胺（CA）神经支配整个声音运动系统中的plainfin见习鱼，Porichtys notatus，季节性繁殖的海洋硬骨鱼，产生声音信号的社会沟通。有两种不同的男性生殖变种在这个物种：I型男性建立巢穴和法院女性与一个长时间的广告呼叫，而II型男性偷偷产卵窃取受精从I型男性。像女性一样，第二型男性只能发出简短的、激动的、咕噜声。在这里，我们测试的假设，CA神经元的数量和它们的纤维神经支配模式在整个声音运动通路的性内差异可能提供的神经基板之间的变异生殖行为的分歧。我们采用免疫荧光（IR）组织化学来测量酪氨酸羟化酶（TH，儿茶酚胺合成的限速酶）神经元数量在几个前脑和后脑核团，以及TH-IR纤维神经支配整个声乐途径在I型和II型男性收集巢在夏季生殖季节。在控制了身体大小的差异后，只有一组CA神经元显示出明确的差异，男性形态：室外迷走神经相关TH-免疫反应神经元，位于两侧的二态性发声运动核（VMN），在数量上显着II型男性。此外，II型男性表现出更大的TH-红外线纤维密度内的VMN和更多的TH-红外线varicosities与假定的联系发声运动神经元。这种强烈的负相关关系之间的主要声乐形态和CA的发声运动神经元的神经支配表明，儿茶酚胺可能起到抑制声音输出在海军军官候补生。这些研究结果支持儿茶酚胺作为直接调制器的声乐行为和差分CA输入出现的社会和生殖行为的男性海军军官候补生变体之间的分歧反映。
Catecholamines, which include the neurotransmitters dopamine and noradrenaline, are known modulators of sensorimotor function, reproduction, and sexually motivated behaviors across vertebrates, including vocal-acoustic communication. Recently, we demonstrated robust catecholaminergic (CA) innervation throughout the vocal-motor system in the plainfin midshipman fish, Porichtys notatus, a seasonal breeding marine teleost that produces vocal signals for social communication. There are two distinct male reproductive morphs in this species: Type I males establish nests and court females with a long duration advertisement call, while type II males sneak-spawn to steal fertilizations from type I males. Like females, type II males can only produce brief, agonistic, grunt-type vocalizations. Here, we tested the hypothesis that intrasexual differences in the numbers of CA neurons and their fiber innervation patterns throughout the vocal-motor pathway may provide neural substrates underlying divergence in reproductive behavior between morphs. We employed immunofluorescence (-ir) histochemistry to measure tyrosine hydroxylase (TH, rate-limiting enzyme in catecholamine synthesis) neuron numbers in several forebrain and hindbrain nuclei as well as TH-ir fiber innervation throughout the vocal pathway in type I and type II males collected from nests during the summer reproductive season. After controlling for differences in body size, only one group of CA neurons displayed an unequivocal difference between male morphs: the extraventricular vagal-associated TH-ir neurons, located just lateral to the dimorphic vocal motor nucleus (VMN), were significantly greater in number in type II males. In addition, type II males exhibited greater TH-ir fiber density within the VMN and greater numbers of TH-ir varicosities with putative contacts on vocal motor neurons. This strong inverse relationship between the predominant vocal morphotype and CA innervation of vocal motor neurons suggests catecholamines may function to inhibit vocal output in midshipman. These findings support catecholamines as direct modulators of vocal behavior and differential CA input appears reflective of social and reproductive behavioral divergence between male midshipman morphs.