Abstract:
The context surrounding vocal communication can have a strong influence on how vocal signals are perceived. The serotonergic system is well-positioned for modulating the perception of communication signals according to context, because serotonergic neurons are responsive to social context, influence social behavior, and innervate auditory regions. Animals like lab mice can be excellent models for exploring how serotonin affects the primary neural systems involved in vocal perception, including within central auditory regions like the inferior colliculus (IC). Within the IC, serotonergic activity reflects not only the presence of a conspecific, but also the valence of a given social interaction. To assess whether serotonin can influence the perception of vocal signals in male mice, we manipulated serotonin systemically with an injection of its precursor 5-HTP, and locally in the IC with an infusion of fenfluramine, a serotonin reuptake blocker. Mice then participated in a behavioral assay in which males suppress their ultrasonic vocalizations (USVs) in response to the playback of female broadband vocalizations (BBVs), used in defensive aggression by females when interacting with males. Both 5-HTP and fenfluramine increased the suppression of USVs during BBV playback relative to controls. 5-HTP additionally decreased the baseline production of a specific type of USV and male investigation, but neither drug treatment strongly affected male digging or grooming. These findings show that serotonin modifies behavioral responses to vocal signals in mice, in part by acting in auditory brain regions, and suggest that mouse vocal behavior can serve as a useful model for exploring the mechanisms of context in human communication.
摘要:
围绕声音交流的上下文可能会对声音信号的感知方式产生重大影响。5-羟色胺能系统很好地定位为根据上下文调制通信信号的感知,因为血清素能神经元对社会环境有反应,影响社会行为,和神经支配听觉区域。像实验鼠这样的动物可以成为探索血清素如何影响声音感知的主要神经系统的绝佳模型,包括像下丘(IC)这样的中央听觉区域。在IC内,血清素能活性不仅反映了一个特定的存在,也是给定社会互动的效价。为了评估血清素是否可以影响雄性小鼠对声音信号的感知,我们通过注射5-羟色胺的前体5-HTP全身操作,在IC局部输注芬氟拉明,5-羟色胺再摄取阻断剂。然后,小鼠参与了一项行为测定,其中雄性抑制其超声发声(USV),以响应雌性宽带发声(BBV)的回放,用于女性与男性互动时的防御性侵略。相对于对照,5-HTP和芬氟拉明在BBV回放期间增加了对USV的抑制。5-HTP还降低了特定类型USV和男性调查的基线产量,但是两种药物治疗都没有强烈影响男性挖掘或修饰。这些发现表明,血清素会改变小鼠对声音信号的行为反应,部分是通过作用于听觉大脑区域,并建议鼠标发声行为可以作为探索人类交流中上下文机制的有用模型。