The subcortical auditory structures in the Mongolian gerbil: II. Frequency-related topography of the connections with cortical field AI
The subcortical auditory structures in the Mongolian gerbil: II. Frequency-related topography of the connections with cortical field AI
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DOI：
10.1002/cne.23314
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发表时间：
2013-08-15
影响因子：
2.5
通讯作者：
Mylius, Judith
中科院分区：
文献类型：
--
作者：
Budinger, Eike;Brosch, Michael;Mylius, Judith
本实验采用两种双向示踪剂同时注入蒙古沙土鼠初级听觉皮层区（AI），观察AI与听觉系统皮层下结构的频率相关性连接。我们发现地形，最有可能的频率匹配（tonotopic）连接以及非地形（non-tonotopic）连接。AI投射到同侧内侧膝状体（MGB）的腹侧部（MGv）和背侧部（MGd）、外侧丘系的网状丘脑核和背侧核、同侧和对侧下丘（IC）的背侧皮质和IC的中央核。AI接收来自MGv和MGd的音调拓扑输入。来自AI不同BF区的投射以非色调定位的方式终止于同侧MGB内侧区（MGm）、丘脑膝上体核（SG）和IC臂（bic）以及同侧和对侧IC外皮质和丘周区。在外侧丘系的中间核和腹侧核、上级橄榄复合体的部分区域和耳蜗核的分区中的顺行标记通常是稀疏的;因此，不能排除标记轴突的明确地形布置。AI接收来自同侧MGm、SG和bic的非音调定位输入。总之，tonotopic和non-tonotopic corticofugal连接的AI可以潜在地服务于在各自的目标结构中的频率特异性信息的保存和整合。神经学比较杂志521：2772-2797，2013。(c)2013 Wiley Periodicals，Inc.
We investigated the frequency-related topography of connections of the primary auditory cortical field (AI) in the Mongolian gerbil with subcortical structures of the auditory system by means of the axonal transport of two bidirectional tracers, which were simultaneously injected into regions of AI with different best frequencies (BFs). We found topographic, most likely frequency-matched (tonotopic) connections as well as non-topographic (non-tonotopic) connections. AI projects in a tonotopic way to the ipsilateral ventral (MGv) and dorsal divisions (MGd) of the medial geniculate body (MGB), the reticular thalamic nucleus and dorsal nucleus of the lateral lemniscus, and the ipsi- and contralateral dorsal cortex of the inferior colliculus (IC) and central nucleus of the IC. AI receives tonotopic inputs from MGv and MGd. Projections from different BF regions of AI terminate in a non-tonotopic way in the ipsilateral medial division of the MGB (MGm), the suprageniculate thalamic nucleus (SG) and brachium of the IC (bic), and the ipsi- and contralateral external cortex and pericollicular areas of the IC. The anterograde labeling in the intermediate and ventral nucleus of the lateral lemniscus, parts of the superior olivary complex, and divisions of the cochlear nucleus was generally sparse; thus a clear topographic arrangement of the labeled axons could not be ruled out. AI receives non-tonotopic inputs from the ipsilateral MGm, SG, and bic. In conclusion, the tonotopic and non-tonotopic corticofugal connections of AI can potentially serve for both conservation and integration of frequency-specific information in the respective target structures. J. Comp. Neurol. 521:2772-2797, 2013. (c) 2013 Wiley Periodicals, Inc.