Physiological Correlates And Neural Mechanisms Of Vocal

Z01 HD 001123 LCE和Z01 HD 001124 LCE是合作项目，共同研究灵长类动物的听觉交流。这些研究的总体目标是从发育、神经机制、内分泌因素和社会环境等方面全面了解灵长类动物的听觉交流。两种非人类灵长类动物，松鼠猴和普通狨猴，是研究的主要对象，并在适当情况下从其他物种收集额外数据。该项目之前的工作表明，人类婴儿哭声的功能和声学等效声音的产生是由位于大脑皮层额叶前中线的边缘皮层介导的，并且听觉皮层（颞上回）中的单个神经元素对物种特定发声的声学结构的细微差异特别敏感。表明在调节个体差异（声音特征）中起重要作用。今年的新发现是：基因c-fos及其蛋白产物Fos已被用于标记在一段时间的强烈行为活动后活动增加的神经区域。对成年松鼠猴大脑中c-fos的表达进行了研究。这个范例包括将个体分开30分钟，记录下？隔离电话吗?将它们放回笼子1小时，然后对它们实施安乐死，并使用免疫细胞化学对它们固定的大脑进行Fos处理。使用6个个体，3个发声良好者和3个发声不良者（30分钟内少于10次）。将放大倍数为200倍的显微照片数字化，然后标记细胞计数。比较了发声者和发声者的3个脑区。这3个区域分别是扣带前回、脑室周围/导水管周围灰质和丘脑背内侧。前两个是在一项研究中发现的，该研究使用大脑损伤来参与分离的松鼠猴的叫声表达；最后一个已知是前扣带的投影区，但未包括在早期的研究中。发声优秀者和发声差者大脑中所有3个区域的标记细胞计数有显著差异。在所有情况下，好的发声者的计数都更高。这些结果表明，c-fos免疫细胞化学是一种有效的替代方法，可以证明灵长类动物大脑中与发声有关的区域的功能参与，并且具有在单个动物中标记整个神经轴结构的优势，而旧的技术，如损伤，需要更多的动物才能给出明确的结果。在第二项研究中，开发了一种创建脑示意图的新方法，作为创建普通狨猴脑图谱的一部分。使用Adobe Photoshop将成年雌性狨猴额部的数字照片设置为标准尺寸。然后这些图像被输入到ImageJ，这是一个由NIH开发的程序。通过反转图像并使用？查找边缘?工具，创建图像的轮廓版本。这些原理图的内部结构仍然可以被识别和标记。这样就可以保留原始的数码照片，而不受任何附加标签的干扰。与此同时，大脑区域内的个体结构可以在示意图中被识别出来，允许未来的地图集用户在给定的大脑区域内找到他们的路。这项工作是由蒙哥马利布莱尔高中的学生雷切尔·贝尔女士在新英格兰大学和NINDS的阿方索·席尔瓦博士的合作下完成的。

Z01 HD 001123 LCE and Z01 HD 001124 LCE are companion projects that together investigate auditory communication in primates. The overall goal of these studies is to provide a comprehensive understanding of primate auditory communication in terms of development, neural mechanisms, endocrine factors, and social context. Two non-human primates, the squirrel monkey and common marmoset, are the main subjects of study, with additional data collected from other species where appropriate. Prior work in this project has shown that production of sounds that are the functional and acoustic equivalents of cry sounds in human infants are mediated by limbic cortex located along the anterior midline of the frontal lobe of the cerebral cortex, and that single neural elements in the auditory cortex (superior temporal gyrus) are particularly responsive to subtle differences in the acoustic structure of species-specific vocalizations, suggesting an important role in mediating individual differences (vocal signatures). New findings this year: The gene c-fos and its protein product Fos, have been used to mark neural regions of increased activity following a period of robust behavioral activity. A study of c-fos expression in adult squirrel monkey brains was conducted. The paradigm involved separating individuals for 30 minutes, recording the ?isolation calls? made during this separation, returning them to their home cage for 1 hour, then euthanizing them and processing their fixed brains for Fos using immunocytochemistry. Six individuals were used, 3 good vocalizers and 3 poor vocalizers (less than 10 calls in 30 minutes). Microphotographs at 200 magnifications were digitized, then labelled cells counted. Fields from 3 brain areas were compared between good vocalizers and poor vocalizers. The 3 areas were the anterior cingulate gyrus, the perventricular/periaqueductal gray, and the dorsomedial thalamus. The first 2 were found in a study using brain lesioning to be involved in expression of calls in separated squirrel monkeys; the last is known to be a projection area to the anterior cingulate, but was not included in the earlier study. Counts of labelled cells were significantly different between all 3 areas in the brains of good and poor vocalizers. In all cases, counts were higher in the good vocalizers. These results indicate that c-fos immunocytochemistry is a valid alternative to demonstrating the functional involvement of primate brain regions involved in vocalizing, and has the advantage of labelling structures throughout the neuraxis in a single animal, whereas older techniques such as lesioning require many more animals to give a clear result. In a second study, a new method for creating schematic brain images was developed as part of the creation of a brain atlas for the common marmoset. Digital photographs of frontal sections from an adult female marmoset were set to a standard size using Adobe Photoshop. The images were then imported into ImageJ, a program developed at the NIH. By inverting the image and using the ?find edges? tool, an outline version of the image was created. The internal structure of these schematic images could still be discerned and labelled. This permitted retention of the original digital photograph, without the distraction of any added labels. At the same time, individual structures within the brain section could be identified in the schematic image, allowing future users of the atlas to find their way around a given brain section. This work was done by Ms. Rachel Bell, a student at Montgomery Blair High School, in a collaboration between the UNE and Dr. Afonso Silva of the NINDS.