Northcutt R G, Butler A B
Neurobiology Unit, Scripps Institution of Oceanography, University of California, San Diego, La Jolla.
Brain Behav Evol. 1993;41(2):57-81. doi: 10.1159/000113824.
The cytoarchitecture of nuclei in the diencephalon and the distribution of acetylcholinesterase (AChE) in the diencephalon and optic tectum were analyzed in the longnose gar, Lepisosteus osseus, a non-teleost actinopterygian fish. Nuclei were identified in the preoptic area, thalamus, posterior tubercle, hypothalamus, synencephalon, and pretectum which are homologous to like-named nuclei in teleosts and other non-teleost actinopterygians. Of particular note, a nucleus in the rostral diencephalon, nucleus rostrolateralis, which has previously been identified only in the osteoglossomorph Pantodon, is present in the long-nose gar. The posterior pretectal nucleus, previously identified in teleosts and in the bowfin Amia, is also present in gars. The small size of the posterior pretectal nucleus in gars supports the hypothesis that this nucleus was small plesiomorphically. The distribution of AChE in the diencephalon and optic tectum corresponds in most respects to that found in teleosts. The superficial pretectal nuclei, including the posterior pretectal nucleus, are strongly positive for AChE. In contrast, most of the nuclei within the preglomerular complex are negative for AChE. Acetylcholinesterase is present in some of the fibers in the optic tracts and in most retinorecipient nuclei, as well as in some other nuclei and tracts.
在长吻雀鳝（Lepisosteus osseus）这种非硬骨鱼辐鳍鱼类中，分析了间脑内核团的细胞结构以及间脑和视顶盖中乙酰胆碱酯酶（AChE）的分布。在视前区、丘脑、后结节、下丘脑、联合脑和顶盖前区识别出了与硬骨鱼和其他非硬骨鱼辐鳍鱼类中同名核团同源的核团。特别值得注意的是，长吻雀鳝中存在一个位于吻端间脑的核团——吻外侧核，该核团此前仅在骨舌鱼目鱼类 Pantodon 中被发现。硬骨鱼和弓鳍鱼 Amia 中先前已识别出的顶盖前核在雀鳝中也存在。雀鳝中顶盖前核体积较小，这支持了该核团在形态学上原本就较小的假说。间脑和视顶盖中 AChE 的分布在大多数方面与硬骨鱼中发现的情况相符。包括顶盖前核在内的浅表顶盖前核团对 AChE 呈强阳性。相比之下，肾小球前复合体中的大多数核团对 AChE 呈阴性。乙酰胆碱酯酶存在于视束的一些纤维中、大多数视网膜接受核中，以及一些其他核团和纤维束中。
