DISSERTATION RESEARCH: Vocal communication in golden hamsters: Behavioral and neural responses of males to female vocal signals

几十年来，科学家们一直对动物如何识别社会交流中使用的特定物种的发声方式感兴趣。听觉信号沿着大脑中的听觉系统进行处理和识别。然而，声音识别还必须涉及其他大脑区域的激活，这些区域影响接收者的内部状态，并随后调节对声音信号的行为反应。为了解决这个问题，研究人员正在研究金黄地鼠在有性环境下产生的超声波发声，以及对这些发声的行为和神经反应。在性交过程中，雄性和雌性仓鼠都表现出不同的发声曲目。这个项目要检验的假设是，超音速波在性别识别中起作用，通过激活与奖励和动机相关的大脑区域，超音速波可以提高性唤醒，并刺激接近声源的行为。这项研究测试了行为反应受多巴胺调节的假设，多巴胺是调节奖赏的关键化合物。初步数据表明，女性比男性发声更多，女性USV的持续时间更长，带宽也比男性更宽。此外，男女的发声都表现出特定的声音特征，可以指示性唤起的水平和呼叫者的动机。本研究是超声心动图研究中的一项关键创新，它综合了：1)声学和统计学分析来验证性别歧视；2)回放实验来验证性别识别；3)神经反应来揭示识别这些心音波行为意义的大脑区域和机制。此外，这项研究还将揭示USVs的其他功能，近年来，USVs在理解生物医学研究中使用的啮齿动物模型物种的社会行为和交流方面变得重要。这项研究也将为STEM本科生提供研究机会。

For decades, scientists have been intrigued by how animals recognize the species-specific vocalizations used in social communication. Auditory signals are processed and recognized along the auditory system in the brain. However, vocal recognition must also involve the activation of other brain regions that affect the internal state of the receiver, and subsequently, modulate the behavioral responses to vocal signals. To address this question, the researchers are studying ultrasonic vocalizations (USVs) produced by the golden hamster in a sexual context, and behavioral and neural responses to these vocalizations. Both male and female hamsters exhibit a diverse vocal repertoire during sexual encounters. The hypothesis to be tested in this project is that USVs function in sex recognition, and by activating brain regions involved with reward and motivation, USVs increase sexual arousal and stimulate approach behavior to the sound source. The research tests the hypothesis that behavioral responses are regulated by dopamine, a critical compound in mediating reward. Preliminary data suggest that females vocalize more than males and that female USVs are longer in duration and have broader bandwidth than male USVs. In addition, the vocalizations of both sexes exhibit specific sound features that could indicate levels of sexual arousal and motivation of the caller. This study represents a key innovation in the study of USVs by integrating: 1) acoustic and statistical analyses of USV to demonstrate sex discrimination, 2) playback experiments to validate sex recognition and 3) neural responses to the USVs to reveal the brain regions and mechanisms involved in recognizing the behavioral significance of these USV. Moreover, this study will shed light onto other functions of USVs, which in recent years have become important in understanding social behavior and communication in rodent model species used in biomedical research. The research will also provide research opportunities for STEM undergraduate students.