Thalamic connections of the auditory cortex in marmoset monkeys: Core and medial belt regions
Thalamic connections of the auditory cortex in marmoset monkeys: Core and medial belt regions
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DOI：
10.1002/cne.20924
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发表时间：
2006-05-01
影响因子：
2.5
通讯作者：
Hackett, TA
中科院分区：
文献类型：
--
作者：
de la Mothe, LA;Blumell, S;Hackett, TA
在这项研究及其同伴中，绒猴听觉皮层内侧带区域的皮层和皮层下连接与核心区域进行了比较。主要目的是记录解剖学特征，这些特征解释了在不同区域之间观察到的功能差异。逆行和双向解剖示踪剂的注射靶向两个核心区域（Al和R）和两个内侧带区域（吻内侧[RM]和尾内侧[CM]）。在内侧膝状体复合体（MGC）和丘脑多感觉核（包括膝状体上核（Sg）、界核（Lim）、内侧枕（PM）和后核（Po））的亚部之间，发现了地形上不同的连接模式。丘脑向CM的主要投射是MGC的前背侧部（MGad），而后背侧部（MGpd）则以RM为靶点。CM也有大量的输入来自多感觉核团，特别是大细胞分裂（MGm）的MGC。RM的多感觉连接较弱。RM和CM的皮质顶盖投影都针对下丘的背内侧象限，而CM投影还包括中央核的腹内侧和外侧部分周围的中央周围延伸。区域Al和R的特点是在MGC的腹侧部（MGV）的局部地形连接，反映了两个核心区域的tonotopic组织。结果表明，平行的皮层下通路的目标核心和内侧带区域和RM和CM代表功能不同的区域内的内侧带听觉皮层。
In this study and its companion, the cortical and subcortical connections of the medial belt region of the marmoset monkey auditory cortex were compared with the core region. The main objective was to document anatomical features that account for functional differences observed between areas. Injections of retrograde and bi-directional anatomical tracers targeted two core areas (Al and R), and two medial belt areas (rostromedial [RM] and caudomedial [CM]). Topographically distinct patterns of connections were revealed among subdivisions of the medial geniculate complex (MGC) and multisensory thalamic nuclei, including the suprageniculate (Sg), limitans (Lim), medial pulvinar (PM), and posterior nucleus (Po). The dominant thalamic projection to the CM was the anterior dorsal division (MGad) of the MGC, whereas the posterior dorsal division (MGpd) targeted RM. CM also had substantial input from multisensory nuclei, especially the magnocellular division (MGm) of the MGC. RM had weak multisensory connections. Corticotectal projections of both RM and CM targeted the dorsomedial quadrant of the inferior colliculus, whereas the CM projection also included a pericentral extension around the ventromedial and lateral portion of the central nucleus. Areas Al and R were characterized by focal topographic connections within the ventral division (MGv) of the MGC, reflecting the tonotopic organization of both core areas. The results indicate that parallel subcortical pathways target the core and medial belt regions and that RM and CM represent functionally distinct areas within the medial belt auditory cortex.