FOREBRAIN CONTROL OF HINDBRAIN VOCAL-PACEMAKER CIRCUITRY

众所周知，所有脊椎动物纲的成员都会在 生殖环境。在接受调查的鱼类和四足纲中 枣(两栖动物、鸟类和哺乳动物)，实验已经建立了一种 前脑在发声调节中的作用 视前区(POA)和腹侧端脑在发声中的作用 监管。后脑运动模式产生电路，该电路 对声带肌肉的神经支配也已在 脊椎动物类。然而，没有任何调查解决这个问题 POA或其他前脑发声中枢如何整合 生殖行为的多样性调节后脑回路来影响 声音输出的变化。 我们假设：(1)视前区(POA)和视网膜区 腹侧端脑对发声行为产生的影响 少校，以及(2)这种前脑调节部分地通过 声带运动的多巴胺和精氨酸血管生成素(AVT)神经支配 网络。这些假设得到了以下数据的有力支持 对于学员和近亲物种：1)发声活动可能是 由电刺激POA和腹侧端脑引起。 2)后脑发声区域周围有密集的多巴胺能 AVT免疫反应(-ir)纤维和终末。3)POA和 腹侧端脑含有大量的多巴胺能细胞 小体，而POA包含Avt-ir细胞小体 军校学员的大脑。 会发声的硬骨鱼提供了唯一的后脑发声系统 已经使用细胞内记录对活动进行了定量监测 技巧。重要的是，学员鱼的发声活动是 与后脑发声神经元放电的同构关系 起搏器-运动神经元(PN-MN)回路。因此，前脑对大脑的调节 可以在PN-MN水平上直接监测发声运动输出 电路和电路的输出可以被分类为 物种--典型的争斗或求偶叫声正在产生。 这里描述的实验的主要目标是确定如何 前脑活动调节节奏活跃的后脑发声 生理、神经化学和解剖层面的运动回路。 这将在普莱芬恩学员(Porichthys Notatus)中执行， 一种硬骨鱼，具有良好的后脑发声PN-MN回路。 我们的首要目标将通过实现四个目标来实现 具体目标：因此，我们将通过测试我们的 通过实现三个具体目标来实现假设：(1)前脑 与已知发声电路的连通性将由 生物素化合物向前脑、中脑和后脑的离子导入 已被识别为发声运动网络一部分的站点 后脑发声运动输出的神经生理学评估 图案生成器。(2)前脑对发声运动回路的调制 将通过向脑内注射多巴胺和AVT来描述 发声运动区，结合发声的神经生理学评估 后脑模式发生器的运动输出。(3)多巴胺能 或声带运动传入的AVT信号特征为 逆行追踪与免疫细胞化学(ICC)联合应用 抗多巴胺和抗动静脉血栓的抗体特性良好。

Members of all vertebrate classes are known to use vocalizations in reproductive contexts. In fish and the tetrapod classes surveyed to date (amphibians, birds and mammals), experiments have established a role for the forebrain in the modulation of vocalizations and have shown the preoptic area (POA) and ventral telencephalon to function in vocal regulation. Hindbrain motor pattern generating circuitry which innervates the vocal musculature has also been outlined in all vertebrate classes. However, no investigations have addressed the issue of how the POA or other forebrain vocal centers which may integrate a variety of reproductive behaviors modulate hindbrain circuitry to effect a change in vocal output. We hypothesize that: (1) the preoptic area (POA) and regions of the ventral telencephalon influence the production of vocal behavior in midshipman, and (2) this forebrain regulation occurs, in part, via dopamine and arginine vasotocin (AVT) innervation of the vocal motor network. These hypotheses are strongly supported by the following data for midshipman and closely related species: 1) Vocal activity may be elicited by electrical stimulation of the POA and ventral telencephalon. 2) The hindbrain vocal region is bordered by a density of dopaminergic and AVT-immunoreactive (-ir) fibers and terminals. 3) The POA and ventral telencephalon contain a large number of dopaminergic cell bodies, while the POA contains all AVT-ir cell bodies present in the midshipman brain. Vocalizing teleost fish provide the only system in which hindbrain vocal activity has been monitored quantitatively using intracellular recording techniques. Importantly, the vocal activity of midshipman fish is isomorphically related to the neuronal firing in the hindbrain vocal pacemaker-motoneuron (PN-MN) circuit. Thus, forebrain modulation of vocal motor output may be monitored directly at the level of the PN-MN circuit and the output of the circuit may be classified as to which species-typical agonistic or courtship vocalization is being generated. The primary goal of the experiments described here is to determine how forebrain activity modulates a rhythmically-active, hindbrain vocal motor circuit at physiological, neurochemical, and anatomical levels. This will be performed in the plainfin midshipman (Porichthys notatus), a teleost fish with a well-characterized hindbrain vocal PN-MN circuit. Our primary goal will be realized through the achievement of four specific aims: Hence, we will address our primary goal by testing our hypotheses through the achievement of three specific aims: (1) Forebrain connectivity to the known vocal circuitry will be investigated by iontophoresis of biotin compounds into forebrain, midbrain and hindbrain sites which have been identified as part of the vocal motor network by neurophysiological assessment of vocal motor output from the hindbrain pattern generator. (2) Forebrain modulation of vocal motor circuitry will be delineated via iontophoretic injection of dopamine and AVT into vocal motor regions, coupled with neurophysiological assessment of vocal motor output from the hindbrain pattern generator. (3) The dopaminergic or AVT signature of vocal motor afferents will be characterized by combined retrograde tract-tracing and immunocytochemistry (ICC) using well characterized antibodies to dopamine and AVT.