Ghashghaei H T, Barbas H
Department of Health Sciences, Boston University, 635 Commonwealth Avenue, Room 431, Boston, MA 02215, USA.
Neuroscience. 2002;115(4):1261-79. doi: 10.1016/s0306-4522(02)00446-3.
The amygdala has been implicated in processing information about the emotional significance of the environment and in the expression of emotions, through robust pathways with prefrontal, anterior temporal areas, and central autonomic structures. We investigated the anatomic organization and intersection of these pathways in the amygdala in rhesus monkeys with the aid of bidirectional, retrograde and anterograde tracers. Connections of the amygdala with orbitofrontal and medial prefrontal areas were robust and bidirectional, whereas connections with lateral prefrontal areas were sparse, unidirectional and ascending. Orbitofrontal axons terminated densely in a narrow band around the borders of the magnocellular basolateral nucleus, surrounded by projection neurons along a continuum through the nuclei of the basal complex. In contrast, the input and output zones of medial prefrontal areas were intermingled in the amygdala. Moreover, medial prefrontal axonal terminations were expansive, spreading into the parvicellular basolateral nucleus, which is robustly connected with hypothalamic autonomic structures, suggesting that they may influence the expressive emotional system of the amygdala. On the other hand, orbitofrontal axons heavily targeted the intercalated masses, which issue inhibitory projections to the central nucleus, at least in rats and cats. The central nucleus, in turn, issues a significant inhibitory projection to hypothalamic and brainstem autonomic structures. This evidence suggests that orbitofrontal areas exercise control on the internal processing of the amygdala. In addition, the results provided direct evidence that the connections of anterior temporal visual and auditory association cortices occupy overlapping territories with the orbitofrontal cortices particularly in the posterior half of the amygdala, and specifically within the intermediate sector of the basolateral nucleus and in the magnocellular part of the basomedial nucleus (also known as accessory basal), suggesting a closely linked triadic network. This intricate network may be recruited in cognitive tasks that are inextricably linked with emotional associations.
杏仁核通过与前额叶、颞前叶区域及中枢自主神经结构的强大通路，参与处理有关环境情感意义的信息及情感表达。我们借助双向、逆行和顺行示踪剂，研究了恒河猴杏仁核中这些通路的解剖组织和交叉情况。杏仁核与眶额叶和内侧前额叶区域的连接强大且双向，而与外侧前额叶区域的连接稀疏、单向且呈上升趋势。眶额叶轴突密集终止于大细胞基底外侧核边界周围的一条窄带，周围是沿基底复合体核连续分布的投射神经元。相比之下，内侧前额叶区域的输入和输出区在杏仁核中相互交织。此外，内侧前额叶轴突终末广泛，延伸至小细胞基底外侧核，该核与下丘脑自主神经结构有强大连接，表明它们可能影响杏仁核的情感表达系统。另一方面，眶额叶轴突大量靶向插入核团，至少在大鼠和猫中，这些核团向中央核发出抑制性投射。中央核则反过来向下丘脑和脑干自主神经结构发出显著的抑制性投射。这一证据表明眶额叶区域对杏仁核的内部处理过程进行控制。此外，结果提供了直接证据，表明颞前视觉和听觉联合皮层的连接与眶额叶皮层占据重叠区域，特别是在杏仁核后半部分，具体位于基底外侧核的中间区域和基底内侧核（也称为副基底）的大细胞部分，提示存在紧密相连的三元网络。这个复杂的网络可能在与情感关联紧密相关的认知任务中被调用。
