Generating sexually differentiated vocal patterns

描述（由申请人提供）：本研究的目的是确定运动前电路是如何产生发声模式的，并比较女性和男性在导致性别差异发声方面的差异。与发声有关的神经元功能信息对于理解发声和构音障碍等疾病至关重要。虽然前脑模式发生器已经在其他系统中得到了很好的表征，但产生发声的髓质回路仍然知之甚少。由于非洲爪蟾的发声不受呼吸的影响，因此相对于其他脊椎动物而言，发声被简化了：这一特征提供了一个实验上易于处理的脊椎动物系统，用于研究髓质中的前运动电路。臂旁核同源物DTAM投射到喉部运动核、运动神经元和中间神经元。DTAM刺激期间的神经活动将被分析，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，运动神经元和中间神经元的胞内记录也将被记录下来。结果将决定每个神经元接收什么类型的输入，以及运动神经元和中间神经元对DTAM信号的反应是否不同。这也将有可能评估DTAM输入到运动核是否有性别差异。最后，歌唱青蛙的DTAM神经元的慢性单单元记录将用于确定每次呼叫期间的活动模式。这些研究应该能让我们深入了解发声是如何产生的，以及性别特定行为背后的神经回路的哪些特性。

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.