MECHANISMS OF ULTRASOUND DETECTION

探测超声波（频率超过20千赫）的能力不仅限于脊椎动物中的哺乳动物。相反，美国鲥鱼，一种与鲱鱼有亲缘关系的鱼，可以探测到。沙棘耳显然参与了超声检测，但超声检测的机制尚不清楚。鱼耳有许多在脊椎动物中独一无二的特征。此外，有证据表明，小耳室的感觉上皮的支持结构（主要听觉内器官）可能在功能上类似于哺乳动物Corti器官的高频区。建议的工作是对耳和第八神经进行详细的生理和超微结构分析，以确定如何检测超声波。它还将量化美国鲥鱼和其他相关物种的超声波探测能力，以便更好地了解可以探测到的各种信号。生理学研究将检查每个内耳耳石内器官的反应特征，并确定超声检测涉及的耳区。这些区域的神经反应将被量化。使用细胞外和细胞内技术。超微结构和形态学方法将用于了解耳的结构，以及超声检测的机械适应性。马里兰大学的心理物理学研究将检验在声波和超声波范围内的听觉能力，并描述这些动物在噪音中探测信号的能力。这些研究也将有助于阐明超声检测的精确机制。莫特海洋实验室（佛罗里达州萨拉索塔）的行为研究将有助于描述对回声定位声音的反应，并有助于确定哪些物种对超声波有反应。这些调查将提供一个机会来检查超声检测在一个高度可接近的耳朵。该系统具有作为一个模型系统的潜力，其中耳的超声区域可用于调查。这个系统有可能有助于我们理解毛细胞系统及其神经支配神经元是如何对超声波刺激做出反应的。此外，该系统还可用于分析哺乳动物耳石器官对听力的潜在影响。

The ability to detect ultrasonic sounds (frequencies over 20 kHz) is not limited to mammals among the vertebrates. Instead, American shad, a clupeid fish (related to herring) can detect. The shad ear is clearly involved in ultrasound detection, but the mechanism of ultrasound is detection is not known. The shad ear has a number of characteristics that are unique among vertebrates. Moreover, there is evidence that the support structure of the sensory epithelial of the utricle, the primary auditory endorgan in shad, may be functionally analogous to the high frequency regions of the mammalian organ of Corti. The proposed work is to do a detailed physiological and ultrastructural analysis of the ear and eighth nerve in order to determine how ultrasound is detected. It will also quantify the ultrasound detection capabilities of American shad and other-related species in order to get a better understanding of the kinds of signals that can be detected. Physiological studies will examine the response characteristics of each inner ear otolithic endorgan, and determine the ear region(s) involved with ultrasound detection. Neural responses from these regions will be quantified. Using extracellular and intracellular techniques. Ultrastructural and morphological approaches will be used to understand the structure of the ear, and the mechanical adaptations for ultrasound detection. Psychophysical studies at the University of Maryland will examine hearing capabilities at sonic and ultrasonic ranges, and characterize the ability of these animals to detect signals in noise. These studies will also help elucidate the precise mechanisms of ultrasound detection. Behavioral studies at Mote Marine Laboratory (Sarasota, Florida) will help characterize response to echolocation sounds, and help determine which species are response to ultrasound. These investigations will provide an opportunity to examine ultrasound detection in a highly accessible ear. This system has the potential of serving as a model system where ultrasonic region of the ear is amenable to investigation. This system has the potential for contributing to our understanding of how hair cell systems, and their innervating neurons, are able to respond to ultrasonic stimuli. Moreover, this system could be useful in analysis of how otolithic organs of the ear in mammals can potential contribute to hearing.