Terlou M, Ekengren B
Cell Tissue Res. 1979 Mar 9;197(1):1-21. doi: 10.1007/BF00233550.
The nucleus praeopticus (NPO) is located on both sides of the preoptic recess and is composed of a pars parvocellularis and a pars magnocellularis. Only in the rainbow trout does the pars magnocellularis consist of separately located medium-sized cells and very large cells. Cytologically, three cell types can be distinguished: 1) unipolar cells ending in the cerebrospinal fluid (CSF), 2) bipolar cells also ending in the CSF and forming an axon, and 3) multipolar cells which generally do not have a direct connection with the ventricle. Axons originate from the cell bodies forming the paired preopticohypophysial tract that runs along the border of the diencephalon and the optic tract. A considerable number of NPO fibers leading to the hypophysis makes close contact with the cell bodies of the pars lateralis of the nucleus lateralis tuberis, indicating a functional relationship. Most NPO fibers terminate in the caudal part of the neurohypophysis, around blood capillaries and at the basal lamina of the pars intermedia. Far fewer fibers appear to terminate near the boundary of the neurohypophysis and the rostral and proximal pars distalis. The nucleus lateralis tuberis (NLT) is located in the caudal hypothalamus, beginning at the rostral end of the horizontal commissure and extending caudally beyond the hypophysial stalk. It consists of the partes rostralis, medialis, lateralis and ventrolateralis. In both species the p. rostralis contains small subependymal neurons and some larger ones. Only in the p. medialis of the Atlantic salmon are large cells present. In both species the most prominent part is the p. lateralis, which consists solely of large cells. Cells situated between the p. medialis and the p. lateralis are grouped in the p. ventrolateralis. It was impossible to trace the axons originating in the NLT, since the cyto- and axoplasm could not be stained specifically. The structure of the NPO and NLT in the two salmonid species is compared with that of other teleosts.
视前核（NPO）位于视前隐窝两侧，由小细胞部和大细胞部组成。仅在虹鳟鱼中，大细胞部由分散分布的中等大小细胞和非常大的细胞组成。从细胞学上看，可以区分出三种细胞类型：1）终止于脑脊液（CSF）的单极细胞；2）也终止于脑脊液并形成轴突的双极细胞；3）通常与脑室无直接连接的多极细胞。轴突起源于细胞体，形成成对的视前垂体束，该束沿着间脑和视束的边界走行。大量通向垂体的NPO纤维与外侧结节核外侧部的细胞体紧密接触，表明存在功能关系。大多数NPO纤维终止于神经垂体的尾部，围绕毛细血管和中间部的基膜。在神经垂体与吻部和近端远侧部的边界附近似乎只有很少的纤维终止。外侧结节核（NLT）位于下丘脑尾部，始于水平连合的吻端，并向尾侧延伸超过垂体柄。它由吻部、内侧部、外侧部和腹外侧部组成。在这两个物种中，吻部都含有小的室管膜下神经元和一些较大的神经元。仅在大西洋鲑的内侧部有大细胞。在这两个物种中，最显著的部分是外侧部，它仅由大细胞组成。位于内侧部和外侧部之间的细胞聚集在腹外侧部。由于细胞和轴质无法特异性染色，因此无法追踪起源于NLT的轴突。将这两种鲑科鱼类的NPO和NLT结构与其他硬骨鱼类的结构进行了比较。
