Ruel Jérôme, Wang Jing, Rebillard Guy, Eybalin Michel, Lloyd Ruth, Pujol Rémy, Puel Jean-Luc
INSERM U583-INM, Hôpital Saint Eloi, 80 Avenue Augustin Fliche, BP 74103, 34091 Montpellier cedex 5, France.
Hear Res. 2007 May;227(1-2):19-27. doi: 10.1016/j.heares.2006.08.017. Epub 2006 Nov 1.
This report summarizes recent neuropharmacological data at the IHC afferent/efferent synaptic complex: the type of Glu receptors and transporter involved and the modulation of this fast synaptic transmission by the lateral efferents. Neuropharmacological data were obtained by coupling the recording of cochlear potentials and single unit of the auditory nerve with intra-cochlear applications of drugs (multi-barrel pipette). We also describe the IHC afferent/efferent functioning in pathological conditions. After acoustic trauma or ischemia, acute disruption of IHC-auditory dendrite synapses are seen. However, a re-growth of the nerve fibres and a re-afferentation of the IHC were completely done 5 days after injury. During this synaptic repair, multiple presynaptic bodies were commonly found, either linked to the membrane or "floating" in ectopic positions. In the meantime, the lateral efferents directly contact the IHCs. The demonstration that NMDA receptors blockade delayed the re-growth of neurites suggests a neurotrophic role of NMDA receptors in pathological conditions.
本报告总结了近期在内毛细胞传入/传出突触复合体处获得的神经药理学数据：涉及的谷氨酸受体和转运体类型，以及外侧传出纤维对这种快速突触传递的调节作用。神经药理学数据是通过将耳蜗电位和听神经单单位记录与耳蜗内药物应用（多管移液管）相结合而获得的。我们还描述了病理条件下内毛细胞传入/传出功能。在声创伤或缺血后，可见内毛细胞-听觉树突突触的急性破坏。然而，损伤5天后神经纤维完全重新生长，内毛细胞也完全重新传入。在这种突触修复过程中，通常会发现多个突触前小体，它们要么与膜相连，要么“漂浮”在异位位置。与此同时，外侧传出纤维直接接触内毛细胞。NMDA受体阻断延迟神经突再生的证明表明NMDA受体在病理条件下具有神经营养作用。
