Nieuwenhuys R
J Hirnforsch. 1983;24(5):501-33.
In this paper a survey is presented of the macrostructure and microstructure of the central nervous system of the brachiopterygian fish Erpetoichthys calabaricus, based partly on personal observations and partly on the literature. The spinal cord resembles in its structural organization that of other fish groups. It is, however, remarkable that at lower levels the ventral and dorsal horns are represented by isolated islands of gray without a zona intermedia. In the rhombencephalon the gray matter is arranged in four longitudinal zones or areas which have been termed area ventralis, area intermedioventralis, area intermediodorsalis and area dorsalis. These longitudinal areas coincide largely, but not entirely, with the so-called functional columns of Herrick and Johnston. The most obvious incongruity is that the area intermediodorsalis contains, in addition to the viscerosensory nucleus o the solitary tract, several somatosensory centres. The cerebellum comprises, apart from a pair of large auriculae, a well developed central body. The latter consists of bilateral symmetrical halves which have invaginated into the ventricular cavity. The rostral part of this central body represents the valvula cerebelli, whereas its caudal part represents the corpus cerebelli. Microscopically, the cerebellum contains a molecular layer, a zone of Purkinje cells and a zone of granule cells, but these structures are not arranged in the usual laminated pattern. The medium-sized mesencephalon comprises a ventral tegmentum and a dorsal tectum. The former can be subdivided into a medial zone and a lateral zone. The medial zone may be considered as a direct rostral continuation of the, mainly somatomotor, rhombencephalic area ventralis. The lateral tegmental zone contains, apart from a rather small torus semicircularis, a huge, submeningeally situated, cell mass, which is known as the torus lateralis. The functional significance of this centre is entirely unknown. The tectum shows a distinct laminar pattern which in some respects is more reminiscent to that of anurans than to that of actinopterygian fishes. The fibre systems in the brain stem and spinal cord have not been studied with experimental techniques so far. However, the following pathways could be clearly distinguished in our normal material: (1) several bundles of primary afferent fibres in the rhombencephalic alar plate, (2) a distinct lateral lemniscus, (3) a large fasciculu longitudinalis medialis, comprising vestibulospinal, vestibulomesencephalic and reticulospinal fibres, as well as the giant fibre of Mauthner, (4) a tectobulbar fibre system, (5) a fasciculus retroflexus, (6) a number of fasciculi tegmentales +
本文基于部分个人观察及部分文献，对非洲胎生鳉鱼（Erpetoichthys calabaricus）中枢神经系统的宏观结构和微观结构进行了综述。脊髓在结构组织上与其他鱼类群体相似。然而，值得注意的是，在较低水平处，腹角和背角由孤立的灰质岛代表，没有中间带。在菱脑，灰质排列成四个纵向区域或区域，分别称为腹侧区、中间腹侧区、中间背侧区和背侧区。这些纵向区域在很大程度上但并非完全与赫里克和约翰斯顿所谓的功能柱重合。最明显的不一致之处在于，中间背侧区除了孤束的内脏感觉核外，还包含几个躯体感觉中枢。小脑除了一对大的耳状叶外，还包括一个发育良好的中央体。后者由双侧对称的两半组成，它们已内陷到脑室腔中。这个中央体的前部代表小脑瓣，而其后部代表小脑体。在显微镜下，小脑包含分子层、浦肯野细胞区和颗粒细胞区，但这些结构并非以通常的分层模式排列。中等大小的中脑包括腹侧被盖和背侧顶盖。前者可细分为内侧区和外侧区。内侧区可被视为主要为躯体运动的菱脑腹侧区的直接向前延续。外侧被盖区除了一个相当小的半规管隆凸外，还包含一个巨大的、位于软膜下的细胞团，称为外侧隆凸。这个中枢的功能意义完全未知。顶盖呈现出明显的分层模式，在某些方面，它更让人联想到无尾两栖类动物的顶盖，而不是辐鳍鱼类的顶盖。到目前为止，尚未用实验技术研究脑干和脊髓中的纤维系统。然而，在我们的正常材料中可以清楚地分辨出以下通路：（1）菱脑翼板中的几束初级传入纤维，（2）一条明显的外侧丘系，（3）一个大的内侧纵束，包括前庭脊髓束、前庭中脑束和网状脊髓束，以及莫特纳尔巨纤维，（4）一个顶盖延髓纤维系统，（5）一个回返束，（6）一些被盖束+
