Henry W R, Mulroy M J
Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta 30912-2000, USA.
Hear Res. 1995 Apr;84(1-2):81-90. doi: 10.1016/0378-5955(95)00014-u.
This study presents evidence in support of the hypothesis that one of the sites of failure during noise-induced temporary threshold shift (TTS) is the afferent synapse between auditory hair cells and auditory nerve fibers. Our results show clear evidence indicating changes in the quantity of afferent synapses and the morphology of presynaptic structures in the alligator lizard auditory hair cells during TTS. In TTS hair cells there are statistically significant decreases in: 1) the number of afferent synapses, 2) the number of synaptic vesicles at the afferent synapses, 3) the size of synaptic bodies, and 4) the packing density of synaptic vesicles around the synaptic body. These results suggest that the presynaptic components of the afferent synapse reflect the functional state of the synapse, and that the reduction of these synapses, both in number and component size, contributes to TTS.
噪声诱导的暂时性阈移（TTS）期间的一个失效部位是听觉毛细胞与听神经纤维之间的传入突触。我们的结果显示了明确的证据，表明在TTS期间，美洲蜥蜴听觉毛细胞中传入突触的数量和突触前结构的形态发生了变化。在TTS毛细胞中，有统计学显著下降的方面包括：1）传入突触的数量，2）传入突触处突触小泡的数量，3）突触体的大小，以及4）突触体周围突触小泡的堆积密度。这些结果表明，传入突触的突触前成分反映了突触的功能状态，并且这些突触在数量和成分大小上的减少导致了TTS。
