Avian superior olivary nucleus provides divergent inhibitory input to parallel auditory pathways
Avian superior olivary nucleus provides divergent inhibitory input to parallel auditory pathways
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DOI：
10.1002/cne.20334
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发表时间：
2005-01-03
影响因子：
2.5
通讯作者：
Rubel, EW
中科院分区：
文献类型：
--
作者：
Burger, RM;Cramer, KS;Rubel, EW
鸟类听觉脑干显示并行处理，这是脊椎动物感觉系统的基本特征。专门用于时间处理的核在很大程度上与处理声音其他方面的核分开。这种平行组织的一个可能的例外是上橄榄核 (SON) 向角核 (NA)、大细胞核 (NM)、板层核 (NL) 和对侧 SON (SONc) 提供的抑制输入。我们试图确定单个 SON 神经元是否投射到多个目标，或者单独的神经元群体独立地投射到单个目标核。我们将两种不同的荧光示踪分子引入成对的靶核中，并量化逆行标记的 SON 神经元双标记的程度。在向任何一对同侧目标（NA 和 NM、NA 和 NL、或 NM 和 NL）进行注射的所有病例中，观察到很大比例的双标记 SON 体细胞，这表明许多单独的 SON 神经元投射到多个目标。相反，当注射涉及 SONc 和任何或所有同侧目标时，双重标记很少见，这表明对侧和同侧目标受到主要来自 SON 局部隔离区域的不同 SON 神经元群的支配。因此，在听觉处理的最早阶段，专门处理时间线索的路径与处理其他声学特征的路径之间存在相互作用。我们提出了一个包含这些结果的概念模型，并表明 SON 电路在一定程度上可以抵消耳间时间差处理中的耳间强度差异。 (C) 2004 Wiley-Liss, Inc.
The avian auditory brainstem displays parallel processing, a fundamental feature of vertebrate sensory systems. Nuclei specialized for temporal processing are largely separate from those processing other aspects of sound. One possible exception to this parallel organization is the inhibitory input provided by the superior olivary nucleus (SON) to nucleus angularis (NA), nucleus magnocellularis (NM), and nucleus laminaris (NL) and contralateral SON (SONc). We sought to determine whether single SON neurons project to multiple targets or separate neuronal populations project independently to individual target nuclei. We introduced two different fluorescent tracer molecules into pairs of target nuclei and quantified the extent to which retrogradely labeled SON neurons were double labeled. A large proportion of double-labeled SON somata were observed in all cases in which injections were made into any pair of ipsilateral targets (NA and NM, NA and NL, or NM and NL), suggesting that many individual SON neurons project to multiple targets. In contrast, when injections involved the SONc and any or all of the ipsilateral targets, double labeling was rare, suggesting that contralateral and ipsilateral targets are innervated by distinct populations of SON neurons arising largely from regionally segregated areas of SON. Therefore, at the earliest stages of auditory processing, there is interaction between pathways specialized to process temporal cues and those that process other acoustic features. We present a conceptual model that incorporates these results and suggest that SON circuitry, in part, functions to offset interaural intensity differences in interaural time difference processing. (C) 2004 Wiley-Liss, Inc.