Clascá F, Llamas A, Reinoso-Suárez F
Department of Morphology, School of Medicine, Autónoma University, Madrid, 28029 Spain.
Cereb Cortex. 2000 Apr;10(4):371-99. doi: 10.1093/cercor/10.4.371.
We present a comprehensive analysis of the cortical connections of the insular and adjacent cortical areas in the domestic cat by using microinjections of wheat-germ agglutinin conjugated to horseradish peroxidase. We examined the identity and extent of the cortical fields connected to each area, the relative anatomical weights of the various connections, their laminar origin, and their paths across the cerebral commissures. Our main finding is that despite their relatively small size and close apposition, the connections of the insular and adjacent areas are far more widespread and more specific to each area than previously realized, suggesting that each area is involved in disparate aspects of cortical integration. The granular insular area is linked to a constellation of somatosensory, motor, premotor and prefrontal districts. The dysgranular insular area is chiefly associated with lateral prefrontal and premotor, lateral somatosensory and perirhinal cortices. The dorsal agranular insular area is connected with limbic neocortical fields, while the ventral agranular insular area is associated with an array of olfactory allocortical fields. The anterior sylvian area is associated with visual, auditory and multimodal areas, with the dorsolateral prefrontal cortex, and with perirhinal area 36. The parainsular area is linked to non-tonotopic auditory and ventromedial frontal areas. Trajectories followed by the callosal axons of each of the investigated areas are extremely divergent. As a whole, the picture of the insular region that emerges from this and a parallel study (Clascá et al., J Comp Neurol 384:456-482, 1997) is that of an extreme heterogeneity, both in terms of histological architecture and neural connections. Comparison with earlier published reports on primates suggests that most, but not all, of the areas we investigated in cats may have an direct counterpart within the insula of Old World monkeys.
我们通过使用与辣根过氧化物酶结合的小麦胚芽凝集素进行微量注射，对家猫脑岛及相邻皮质区域的皮质连接进行了全面分析。我们研究了与每个区域相连的皮质区域的特征和范围、各种连接的相对解剖权重、它们的层状起源以及它们穿过大脑连合的路径。我们的主要发现是，尽管脑岛和相邻区域相对较小且相邻，但它们的连接比以前认识到的更为广泛且更具区域特异性，这表明每个区域都参与了不同方面的皮质整合。颗粒状脑岛区域与一系列躯体感觉、运动、运动前区和前额叶区域相连。颗粒减少的脑岛区域主要与外侧前额叶和运动前区、外侧躯体感觉区和梨状周皮质相关。背侧无颗粒脑岛区域与边缘新皮质区域相连，而腹侧无颗粒脑岛区域与一系列嗅觉旧皮质区域相关。前颞叶区域与视觉、听觉和多模态区域、背外侧前额叶皮质以及梨状周区域36相关。岛周区域与非音调定位听觉区域和腹内侧额叶区域相连。每个研究区域的胼胝体轴突所遵循的轨迹极其分散。总体而言，从本研究以及一项平行研究（Clascá等人，《比较神经学杂志》384:456 - 482，1997）中得出的脑岛区域的情况是，在组织学结构和神经连接方面都存在极端的异质性。与早期发表的关于灵长类动物的报告相比，表明我们在猫身上研究的大多数（但不是全部）区域可能在旧世界猴的脑岛内有直接对应区域。
