Department of Psychology, Tennessee State University, Nashville, Tennessee 37209, USA.
Anat Rec (Hoboken). 2012 May;295(5):800-21. doi: 10.1002/ar.22451. Epub 2012 Mar 28.
The current working model of primate auditory cortex is constructed from a number of studies of both new and old world monkeys. It includes three levels of processing. A primary level, the core region, is surrounded both medially and laterally by a secondary belt region. A third level of processing, the parabelt region, is located lateral to the belt. The marmoset monkey (Callithrix jacchus jacchus) has become an important model system to study auditory processing, but its anatomical organization has not been fully established. In previous studies, we focused on the architecture and connections of the core and medial belt areas (de la Mothe et al., 2006a, J Comp Neurol 496:27-71; de la Mothe et al., 2006b, J Comp Neurol 496:72-96). In this study, the corticocortical connections of the lateral belt and parabelt were examined in the marmoset. Tracers were injected into both rostral and caudal portions of the lateral belt and parabelt. Both regions revealed topographic connections along the rostrocaudal axis, where caudal areas of injection had stronger connections with caudal areas, and rostral areas of injection with rostral areas. The lateral belt had strong connections with the core, belt, and parabelt, whereas the parabelt had strong connections with the belt but not the core. Label in the core from injections in the parabelt was significantly reduced or absent, consistent with the idea that the parabelt relies mainly on the belt for its cortical input. In addition, the present and previous studies indicate hierarchical principles of anatomical organization in the marmoset that are consistent with those observed in other primates.
目前灵长类听觉皮层的工作模型是基于对新旧大陆猴的多项研究构建的。它包括三个处理层次。一个主要层次，即核心区域，被内侧和外侧的次级带区域包围。第三个处理层次，即副带区域，位于带的外侧。绒猴（Callithrix jacchus jacchus）已成为研究听觉处理的重要模型系统，但它的解剖结构尚未完全确定。在之前的研究中，我们专注于核心和内侧带区域的结构和连接（de la Mothe 等人，2006a，J Comp Neurol 496：27-71；de la Mothe 等人，2006b，J Comp Neurol 496：72-96）。在这项研究中，我们检查了绒猴外侧带和副带的皮质皮质连接。示踪剂被注射到外侧带和副带的头侧和尾侧部分。这两个区域都显示出沿前后轴的拓扑连接，其中注射的尾侧区域与尾侧区域具有更强的连接，而注射的头侧区域与头侧区域具有更强的连接。外侧带与核心、带和副带具有强烈的连接，而副带与带具有强烈的连接，但与核心没有强烈的连接。来自副带注射的核心中的标记明显减少或缺失，这与副带主要依赖带获得皮质输入的观点一致。此外，目前和以前的研究表明，绒猴的解剖组织具有与其他灵长类动物一致的层次组织原则。
