TRANSMISSION AT THE INNER HAIR CELL AFFERENT SYNAPSE

这是一个多学科研究的突触传递之间的。 哺乳动物耳蜗内毛细胞和放射状传入纤维 螺旋神经节的神经元。它的目的是为了第一次描述 对IHC释放递质的时间进行计时，以检查 钙在介导递质释放中的作用及其启动 该系统中的突触后动作电位。的另一个组件 研究将确定突触传递的形态相关性 在发射器释放速率不同的情况下 在IHC掺入示踪剂辣根过氧化物酶之后 (HRP)在超微结构水平上。突触的生理学将是 通过其附近的放射状传入神经的细胞内记录进行评估 与内耳毛细胞的突触接触点和单次记录 外淋巴管同时灌流时的耳蜗神经传入 含有改变的二价阳离子含量的溶液的空间。这个 供应放射状传入神经的活动区的数目和超微结构 通过连续重建它们在毛细胞上的末端进行评估 高压电子显微镜(HVEM)观察。远景目标是 为这种感觉突触建立一个基于物理的模型。这项研究已经 对公共卫生的影响，因为它将为研究 可能特别影响突触的药物和疾病机制。

This is a multidisciplinary study of synaptic transmission between the inner hair cells (IHC) of the mammalian cochlea and the radial afferent neurons of the spiral ganglion. Its purpose is to describe for the first time the quantal release of transmitter by IHCs, to examine the role of calcium in mediating transmitter release and the initiation of postsynaptic action potentials in this system. Another component of the study will be to identify morphological correlates of synaptic transmission by the IHCs under conditions of varying rates of transmitter release by following the incorporation by IHCs of the tracer horseradish peroxidase (HRP) at the ultrastructural level. The physiology of the synapse will be assessed by intracellular recording from the radial afferents near their points of synaptic contact with the OHCs and by recording from single cochlear nerve afferents during simultaneous perfusion of the perilymphatic spaces with solutions containing altered divalent cation content. The number and ultrastructure of active zones supplying radial afferents will be assessed by serially reconstructing their terminations on the hair cells with high voltage electron microscopy (HVEM). The long range goal is to develop a physically-based model of this sensory synapse. The study has public health implications in that it will open the way for the study of drug and disease mechanisms which may specifically affect the synapse.