The temporal organization of mouse ultrasonic vocalizations

House mice, like many tetrapods, produce multielement calls consisting of individual vocalizations repeated in rhythmic series. In this study, we examine the multielement ultrasonic vocalizations (USVs) of adult male C57Bl/6J mice and specifically assess their temporal properties and organization. We found that male mice produced two classes of USVs which displayed unique temporal features and arose from discrete respiratory patterns. Nearly all USVs were produced in repetitive series exhibiting a hierarchical organization and a stereotyped rhythmic structure. Furthermore, series rhythmicity alone was determined to be sufficient to mathematically discriminate the USVs of adult males from adult females and pups, underscoring the known importance of call timing in USV perception. Finally, the gross spectrotemporal features of male USVs were found to develop continuously from birth and stabilize by P50, suggesting that infant and adult USVs rely on common biological mechanisms. In conclusi...与多数四足动物相仿，家鼠可发出多元素鸣声，这类鸣声由单个发声单元按节律性序列重复构成。本研究针对成年雄性C57Bl/6J小鼠的多元素超声发声（ultrasonic vocalizations, USVs）展开分析，重点评估其时间特性与组织结构。研究发现，雄性小鼠可产生两类超声发声，二者具备独特的时间特征，且源自不同的呼吸模式。几乎所有超声发声均以重复序列形式产生，呈现出层级化组织结构与定型化节律结构。此外，仅依靠序列节律性即可通过数学方法区分成年雄性、成年雌性与幼崽的超声发声，这进一步印证了发声时序在超声发声感知中的已知重要性。最后，研究观察到雄性小鼠超声发声的整体谱时域特征从出生起便持续发展，并在出生后第50天（P50）趋于稳定，表明幼崽与成年个体的超声发声依赖共同的生物学机制。综上，