Lin X, Chen S, Chen P
Department of Cell and Molecular Biology, House Ear Institute, Los Angeles, CA 90057, USA.
Neuroreport. 2000 Apr 7;11(5):957-61. doi: 10.1097/00001756-200004070-00012.
The lateral olivocochlear efferent (LOC) fibers form axodendritic synapses with auditory nerve dendrites synapsing on inner hair cells to affect postsynaptic responses GABA is one of the primary transmitters used by the LOC efferent. However, the molecular nature and developmental expression of the GABA receptors in spiral ganglion (SG) neurons are poorly understood. We have identified the GABAB receptors in SG neurons of mice by pharmacological criteria and polymerase chain reaction (PCR) detection. Applications of GABA or baclofen increased intracellular Ca2+ concentrations and inhibited glutamate responses. The responses were blocked by saclofen, but not by bicuculline. Relative-quantitative PCR showed that GABAB receptors were expressed prenatally, and their levels did not change significantly during the maturation of SG neurons.
外侧橄榄耳蜗传出（LOC）纤维与在传入内毛细胞上形成突触的听神经树突形成轴突-树突突触，以影响突触后反应。GABA是LOC传出纤维使用的主要递质之一。然而，螺旋神经节（SG）神经元中GABA受体的分子特性和发育表达情况却知之甚少。我们通过药理学标准和聚合酶链反应（PCR）检测，在小鼠的SG神经元中鉴定出了GABAB受体。应用GABA或巴氯芬可增加细胞内Ca2+浓度并抑制谷氨酸反应。这些反应被赛氯芬阻断，但未被荷包牡丹碱阻断。相对定量PCR显示，GABAB受体在出生前就已表达，且在SG神经元成熟过程中其水平无明显变化。
