Nitecka L M, Sobkowicz H M
Department of Neurology, University of Wisconsin-Madison 53706, USA.
Hear Res. 1996 Sep 15;99(1-2):91-105. doi: 10.1016/s0378-5955(96)00088-3.
Stains with antibodies to glutamic acid decarboxylase (GAD) and gamma-aminobutyric acid (GABA) in the cochlea of postnatal and adult mice reveal within the inner spiral bundle a distinctive neuronal plexus intimately associated with the inner hair cells. This innervation provides endings that cradle the receptor poles of the sensory cells and lateral end collaterals that wind between the cells, distributing endings alongside and around them. Some GAD-positive fibers enter the inner pillar bundle, from where they distribute tunnel fibers to the outer hair cells and recurrent collaterals to the inner hair cells. The GABAergic innervation within the inner spiral bundle is present along the entire cochlear axis, with the highest density in its basal half. Stainings against calcitonin gene-related peptide (CGRP), which localizes in the cholinergic counterpart of the inner spiral bundle, reveal that some of these fibers parallel the GABAergic circuit. The present data, together with our previous demonstration of compound (serial, converging, triadic) efferent synapses within this pathway (Sobkowicz et al. (1995) Abst. ARO 18, 171) evidences the presence of a distinctive innervation to the inner hair cells, hitherto unrecognized. The expression of growth-associated protein-43 (GAP-43) within the inner hair cell innervation in the adult cochlea provides evidence for a continuous synaptic turnover and plasticity, thus emphasizing its functional importance.
用抗谷氨酸脱羧酶（GAD）和γ-氨基丁酸（GABA）抗体对新生和成年小鼠耳蜗进行染色，结果显示在内螺旋束内存在一个与内毛细胞密切相关的独特神经丛。这种神经支配提供了环绕感觉细胞受体极的终末以及在细胞之间蜿蜒的外侧终末侧支，并在它们旁边和周围分布终末。一些GAD阳性纤维进入内柱束，从那里它们向外毛细胞分布隧道纤维，并向内毛细胞分布返回侧支。内螺旋束内的GABA能神经支配沿整个耳蜗轴存在，在其基底部密度最高。针对降钙素基因相关肽（CGRP）的染色显示，其中一些纤维与GABA能回路平行，CGRP定位于内螺旋束的胆碱能对应物中。目前的数据，连同我们之前在该通路中证明的复合（串联、汇聚、三联体）传出突触（Sobkowicz等人，（1995年）ARO摘要18，171），证明了存在一种迄今未被认识的对内毛细胞的独特神经支配。成年耳蜗内毛细胞神经支配中生长相关蛋白43（GAP - 43）的表达为持续的突触更新和可塑性提供了证据，从而强调了其功能重要性。
