Valverde F, López-Mascaraque L, De Carlos J A
Laboratorio de Neuroanatomía Comparada, Instituto de Neurobiología, Santiago Ramón y Cajal, CSIC, Madrid, Spain.
J Comp Neurol. 1989 Jan 22;279(4):581-600. doi: 10.1002/cne.902790407.
The cytoarchitecture, topography, and cellular structure of the nucleus olfactorius anterior (NOA) in the hedgehog have been studied in Nissl-stained and Golgi preparations. The NOA is an important receptive allocortical formation for olfactory fibers and the major source of association fibers relating the main olfactory bulb with the rest of the olfactory brain. It was divided into a bulbar part; four subdivisions named lateral, dorsal, medial, and ventral; an external part; and a posterior part. Except for the external and posterior subdivisions, the NOA is relatively homogeneous and, in spite of the apparent lack of sublamination in Niss-stained material, four clearly defined cellular laminae were distinguished by the Golgi method. These layers were found to be strikingly similar to those in the piriform cortex. Layer I contains the terminal ramifications of apical dendrites of pyramidal cells and the collaterals of the lateral olfactory tract. The superficial part of layer II contains extraverted pyramidal cells with two or three apical dendrites ramifying in layer I. Most pyramidal cells in the deep part of layer II and layer III are typical pyramidal cells with axons entering the commissura anterior. Some pyramidal cell axons bifurcate into two branches running in opposite directions in the commissura anterior. The interstitial zone below layer III contains deep pyramidal cells and polymorphic cells with ascending branches. Cells with intrinsic axons were classified into four main categories according to the distribution of their axonal ramifications: 1) cells with very restricted axons, 2) cells with axons oriented tangentially in the superficial part of layer II, 3) cells with ascending axons located in the deep part, and 4) chandelierlike cells. Finally, some functional considerations are discussed.
在刺猬中，已通过尼氏染色和高尔基染色制剂研究了前嗅核（NOA）的细胞结构、局部解剖学和细胞结构。前嗅核是嗅觉纤维的重要感受性异生皮质结构，也是将主嗅球与嗅觉脑其余部分相连的联合纤维的主要来源。它被分为一个球部；四个亚区，分别称为外侧、背侧、内侧和腹侧；一个外部和一个后部。除了外部和后部分区外，前嗅核相对均匀，尽管在尼氏染色材料中明显缺乏分层，但通过高尔基方法可区分出四个清晰定义的细胞层。发现这些层与梨状皮质中的层非常相似。I层包含锥体细胞顶树突的终末分支和外侧嗅束的侧支。II层浅部包含外向型锥体细胞，其有两到三个顶树突在I层分支。II层深部和III层中的大多数锥体细胞是典型的锥体细胞，其轴突进入前连合。一些锥体细胞轴突在前连合中分为两个向相反方向延伸的分支。III层下方的中间带包含深部锥体细胞和具有上升分支的多形细胞。根据其轴突分支的分布，具有固有轴突的细胞分为四大类：1）轴突非常受限的细胞，2）轴突在II层浅部切向排列的细胞，3）轴突位于深部的上升型细胞，4）吊灯样细胞。最后，讨论了一些功能方面的考虑因素。
