Gene expression and signal classification in the auditory system of bats

描述（申请人提供）：小棕蝠（Myotis lucifugus）具有高超的回声定位能力；它们可以利用声纳系统在黑暗中导航、探测、识别、定位和跟踪猎物。它们的回声定位信号已经被详细研究过，但它们的交流叫声在社会互动中被广泛使用，例如在母子互动中，以及在防御或宣传觅食区域时，它们的特征却不太明显。本研究的目的是表征和确定小棕蝠的声音交流信号的行为相关性，并研究处理这些声音的解剖学基础。本研究将对夜间蝙蝠个体的交流叫声进行记录，并开发一种自动分类算法对记录的叫声进行客观分类。为了研究参与通信信号处理的解剖结构，将使用即时早期基因ZENK （zif268, egr1, NGFI-A, krox-24）作为脑激活的分子标记。在鸣禽中，在接触到自己的歌声或同种的歌声（即同一物种的歌声）后，ZENK在处理这些歌曲的特定大脑区域中上调。最近对青蛙的一项研究也表明，ZENK在青蛙听觉中脑的孤立区域显示出依赖于呼叫的激活。这些研究表明，ZENK可以用来阐明通信信号处理的解剖学基础。为了确定每种呼叫类型的行为相关性，将单个呼叫回放给蝙蝠，并对蝙蝠的反应进行视听调查。蝙蝠的听觉系统已经成为研究语音处理的一个有用的模型（由于蝙蝠的回声定位[和交流]呼叫与人类语音之间的声音特征，以及它们听觉系统的结构和功能组织之间的相似性）。这项提议的研究将阐明复杂自然声音的神经处理过程。

DESCRIPTION (provided by applicant): Little brown bats (Myotis lucifugus) have exquisite ability to echolocate; they can utilize their sonar system to navigate, and detect, identify, locate and track prey, in darkness. Their echolocation signals have been studied in detail but their communication calls are less well characterized despite the widespread use during their social interactions, e.g. in mother-young interactions, and in defending or advertising feeding areas. The goals of this study are to characterize, and determine the behavioral relevance of, sound communication signals of little brown bats, as well as to investigate the anatomical substrates for processing of these calls. The communication calls of M. lucifugus will be recorded from individual bats overnight, and an automatic classification algorithm will be developed to objectively classify the recorded calls. To study the anatomical structures involved in processing of the communication signals, the immediate early gene ZENK (zif268, egr1, NGFI-A, krox-24) will be used as a molecular marker for brain activation. In songbirds, after exposure to the bird's own songs or conspecific songs (i.e., songs within their species), ZENK is upregulated in specific brain areas involved in processing of these songs. A recent study in frogs also showed that ZENK displays call-dependent activation in isolated regions of the frog auditory midbrain. These studies demonstrate that ZENK can be used to elucidate the anatomical substrates of processing of communication signals. To determine the behavioral relevance of each call type, individual calls will be played back to a bat, and the bat's response investigated audio-visually. The bat auditory system has served as a useful model for studying speech processing (due to the similarities in sound features between bat's echolocation [and communication] calls and human speech sounds, and in structural and functional organizations of their auditory systems). The proposed study would shed light on the neural processing of complex natural sounds.