BASIC AND CLINICAL STUDIES OF THE AUDITORY SYSTEM

为了开发听力障碍治疗的合理依据，四个 大波士顿地区的机构加入了一个 多学科小组开展生理机制研究 它们在脊椎动物的听觉中运作。定义了系统的五个阶段 学习：1.)中耳将声音从外部传递到 内耳。物理变量的测量，如声压、 听小骨的运动，耳蜗声输入阻抗是在 精选脊椎动物。声传播的数学模型 中耳是从这些数据和中耳的效果中产生的 探索肌肉收缩；2)转导的耳蜗牛 对神经活动产生声学刺激。两国之间的关系 听神经纤维对毛细胞形态的反应 神经支配和周围神经支配模式将通过 蜥蜴生理识别纤维的细胞内标记 耳蜗骨。毛细胞传递器(S)的化学性质将是 借助于对富含鱼类器官的提取物敏感的生物测定进行研究 在毛细胞中；3)为大脑提供输入的听神经 从耳朵传来的。语音信息的编码将通过以下方式来解决 麻醉大鼠听神经有髓纤维的记录 猫。来自螺旋神经节神经元的录音产生了小的， 将在豚鼠身上尝试在听神经中建立无髓鞘纤维； 4.)耳蜗核是大脑中第一个听觉核团。这个 脑内无髓纤维的中枢投射和联系 听神经在耳蜗核的分支将被跟随。 成年猫。无髓鞘神经末梢的大体分布 纤维和亲本细胞体的形态将通过 (五)免疫学方法。中枢神经通路提供了 大脑中处理听觉信号的神经元回路。二 将研究反馈机制。第一个是中耳肌 反射途径，这将在猫身上定义和研究。第二个是 将在手术患者中检查的耳蜗传出供应 通过测试人类的生理反应和心理物理表现 切断橄榄耳蜗束前后。在另一组 研究表明，人类的双耳知觉与诱发电位有关。

In order to develop rational bases for treatment of hearing disorders, four institutions of the greater Boston area have joined in forming a multidisciplinary group to conduct research on the physiological mechanisms that operate in vertebrate hearing. Five stages of the system are defined for study: 1.) The middle-ear which transmits sound from the external to the inner ear. Measurements of physical variables such as sound pressure, ossicular movement, acoustic input impedance to the cochlea are made in selected vertebrates. Mathematical models for sound transmission through the middle ear are generated from these data and effects of the middle-ear muscle contractions are explored; 2.) The cochler where transduction of accoustic stimuli to neural activity occur. The relationship of auditory-nerve fiber responses to the morphology of the hair cells innervated and the peripheral innervation pattern will be studied by intracellularly marking physiologically identified fibers in the lizard cochlea. The chemical nature of the hair-cell transmitter(s) will be studied with the aid of bioassays sensitive to extracts of fish organs rich in hair cells; 3.) The auditory nerve which provides the input to the brain from the ear. The coding of speech information will be addressed by recording from myelinated fibers in the auditory nerve of anesthetized cats. Recordings from spiral ganglion neurons giving rise to the small, unmyelinated fibers in the auditory nerve will be attempted in guinea pigs; 4.) The cochlear nucleus is the first auditory nucleus in the brain. The central projections and connections of the unmyelinated fibers in the auditory nerve will be followed as they ramify in the cochlear nucleus of adult cats. The gross distribution of the endings from the unmyelinated fibers and the morphology of the parent cell bodies will be explored by immunological methods; and 5.) The central neural pathways that provide the neuronal circuitry in the brain for processing auditory signals. Two feedback mechanisms will be studied. The first is the middle-ear-muscle reflex pathway, which will be defined and studied in cats. The second is the cochlear efferent supply, which will be examined in surgical patients by testing physiological responses and psychophysical performance in humans before and after the olivocochlear bundle is cut. In another set of studies, binaural perception will be related to evoked potentials in man.