Generating sexually differentiated vocal patterns

描述(申请人提供)：这项研究的目的是确定运动前回路如何产生发声模式，并比较导致性别差异发声的女性和男性的差异。将神经元功能与发声联系起来的信息对于理解发声和构音障碍等障碍是必不可少的。虽然前脑模式发生器在其他系统中已经很好地描述了特征，但对产生发声的延髓回路仍然知之甚少。由于非洲爪哇的发声从呼吸中解放出来，相对于其他脊椎动物来说，发声被简化了：这一特征提供了一个实验上易于驯化的脊椎动物系统，在其中研究延髓中的运动前回路。臂旁核的同系物DTAM投射到喉运动核、运动神经元和中间神经元。将分析DTAM刺激期间的神经活动，以评估运动前模式是如何形成运动输出的。在DTAM刺激过程中，还将记录运动神经元和中间神经元的细胞内记录。结果将决定每个神经元接受什么类型的输入，以及运动神经元和中间神经元是否对DTAM信号做出不同的反应。也有可能评估DTAM对运动核团的输入是否具有性别差异。最后，鸣蛙DTAM神经元的长期单位记录将被用来确定每次叫声期间的活动模式。这些研究应该能洞察发声是如何产生的，以及神经回路的哪些特性不符合性别特有的行为。

DESCRIPTION (provided by applicant): The aim of this research is to determine how premotor circuitry generates vocal patterns, and to compare differences in females and males that lead to sexually distinct vocalizations. Information relating neuronal function with vocalization is essential to understanding phonation and disorders such as dysarthrias. While forebrain pattern generators have been well characterized in other systems, medullary circuits producing vocalizations remain poorly understood. Because Xenopus vocalization is emancipated from respiration, vocalization is simplified relative to other vertebrates: this feature provides an experimentally tractable vertebrate system in which to study premotor circuitry in the medulla. A parabrachial nucleus homologue, DTAM, projects to laryngeal motor nucleus motoneurons and interneurons. Nerve activity during DTAM stimulation will be analyzed to assess how premotor patterns are shaped into motor output. Intracellular recordings of motoneurons and interneurons will be also be made during DTAM stimulation. Results will determine of what types of input each neuron receives, and whether motoneurons and interneurons respond differentially to DTAM signals. It will also be possible to assess whether DTAM inputs to the motor nucleus are sexually distinct. Finally, chronic single-unit recordings of DTAM neurons in singing frogs will be used to determine activity patterns during each call. These studies should provide insight into how vocalizations are produced and what properties of the neural circuitry underly sex-specific behaviors.