Structure-Function Studies of a Sonic (Acoustic) Motor System

在过去的十年中，人们研究了许多模型系统，试图了解脊椎动物行为中两性异形的细胞相关性。这方面的大部分工作都集中在控制社交信号产生的神经元和肌肉上，这些信号在繁殖季节的繁殖行为中起着重要作用。在所有这些系统中研究两性二态性的主要优点是，通信信号——一首歌、一声呼叫或一种电子器官放电——在外观上是固定的，容易量化，并由一组离散的肌肉和中枢神经元控制。安德鲁·巴斯博士对生理上鉴定的两性二态细胞的结构-功能研究感兴趣。本研究项目涉及鱼类控制声音通信信号产生的运动系统的研究。所选择的系统是海洋硬骨鱼的鳔或声波运动系统。声信号是由一组由中央运动核控制的肌肉产生的，这可能与四足动物的舌下运动核相当。巴斯博士发现，在一组海洋硬骨鱼（Porichthys notatus）中，控制声音产生的肌肉的大体和超微结构特征存在显著的性别差异。在行为上也存在性别差异，因为只有雄性才有声音。虽然这个研究项目的主要目标是描述男性海军军官见习生声音运动系统的结构-功能组织，但同样的研究将在女性身上进行，以阐明该系统中的性别二态性。这样的研究将导致更好地描述实验，以了解脊椎动物大脑行为中两性异形发展的细胞机制。

During the past decade a number of model systems have been studied in attempts to understand the cellular correlates of sexual dimorphisms in the behavior of vertebrates. Much of this work has focused on neurons and muscles controlling the production of social communication signals that play a major role in reproductive behavior during breeding seasons. The principal advantages in studying sexual dimorphisms in all of these systems is that the communication signal--a song, a call, or an electric organ discharge--is stereotyped in appearance, easily quantifiable and controlled by a discrete set of muscles and central neurons. Dr. Andrew Bass is interested in structure- function studies of physiologically identified cells which are sexually dimorphic. This research project concerns studies of a motor system controlling the production of sound communication signals in fishes. The system chosen is the swimbladder or sonic motor system of marine teleosts. The acoustic signal is produced by a single set of muscles which are controlled by a central motor nucleus that may be comparable to the hypoglossal motor nucleus of tetrapods. Dr. Bass has discovered a dramatic sex difference in the gross and ultrastructural features of the muscles controlling sound production in one group of marine teleosts, the midshipmen, Porichthys notatus. There is also a behavioral sex difference in that only males are known to be sonic. Although a major goal of this research project is characterization of structure-function organization in the sonic motor system of male midshipmen, the same studies will be carried out with females to elucidate sexual dimorphisms in the system. Such studies will lead to more well delineated experiments for understanding the cellular mechanisms underlying the development of sexual dimorphisms in the brain behavior of vertebrates.