Suneja S K, Benson C G, Potashner S J
Department of Anatomy, University of Connecticut Health Center, 263 Farmington Avenue, Farmington, Connecticut, 06030, USA.
Exp Neurol. 1998 Dec;154(2):473-88. doi: 10.1006/exnr.1998.6946.
In young adult guinea pigs, the effects of unilateral cochlear ablation were determined on the specific binding of [3H]strychnine measured in subdivisions of the cochlear nucleus (CN), the superior olivary complex, and the auditory midbrain, after 2, 7, 31, 60, and 147 postlesion days. Changes in binding relative to that in age-matched controls were interpreted as altered activity and/or expression of synaptic glycine receptors. Postlesion binding declined ipsilaterally in most of the ventral CN and in the lateral superior olive (LSO). Binding was modestly deficient in the ipsilateral dorsal CN and in the anterior part of the contralateral anteroventral CN. Binding was elevated in the contralateral LSO. Transient changes also occurred. Binding was elevated transiently, between 2 and 31 days, contralaterally in parts of the anteroventral CN, bilaterally in the medial superior olive (MSO), and bilaterally in most of the midbrain nuclei. Binding was deficient transiently, at 60 days, in most of the contralateral CN and bilaterally in the midbrain nuclei. The present findings, together with previously reported postlesion changes in glycine release, were consistent with persistently weakened glycinergic inhibitory transmission ipsilaterally in the ventral CN and the LSO and bilaterally in the dorsal CN. Glycinergic inhibitory transmission was strengthened in the contralateral LSO and transiently strengthened in the MSO bilaterally. A hypothetical model of the findings suggested that glycine receptor regulation may depend on excitatory and glycinergic input to auditory neurons. The present changes in glycine receptor activity may contribute to altered auditory functions, which often accompany hearing loss.
在年轻成年豚鼠中，研究了单侧耳蜗切除术后2、7、31、60和147天，耳蜗核（CN）各亚区、上橄榄复合体和听觉中脑内[3H]士的宁特异性结合的变化。与年龄匹配的对照组相比，结合的变化被解释为突触甘氨酸受体活性和/或表达的改变。术后，大多数腹侧CN和外侧上橄榄核（LSO）的同侧结合下降。同侧背侧CN和对侧前腹侧CN前部的结合略有不足。对侧LSO的结合增加。还出现了短暂变化。在2至31天之间，前腹侧CN的部分区域对侧、内侧上橄榄核（MSO）双侧以及大多数中脑核团双侧的结合短暂升高。在60天时，大多数对侧CN和中脑核团双侧的结合短暂不足。目前的研究结果，连同先前报道的损伤后甘氨酸释放的变化，与腹侧CN和LSO同侧以及背侧CN双侧甘氨酸能抑制性传递持续减弱一致。对侧LSO的甘氨酸能抑制性传递增强，双侧MSO的甘氨酸能抑制性传递短暂增强。研究结果的一个假设模型表明，甘氨酸受体调节可能取决于听觉神经元的兴奋性和甘氨酸能输入。目前甘氨酸受体活性的变化可能导致听觉功能改变，而听觉功能改变常伴随听力损失。
