Oelschläger H A
Department of Anatomy, Johann Wolfgang Goethe-University, Frankfurt am Main, FRG.
Brain Behav Evol. 1989;34(3):171-83. doi: 10.1159/000116503.
The development of the olfactory and terminalis systems was studied in tissue from eight embryonic and early fetal specimens belonging to three species of baleen whales. In contrast to toothed whales, baleen whales, particularly in these ontogenetic stages, are much less specialized in nasal organ morphology. The nasal cavity and peripheral olfactory system are well developed and do not show signs of reduction. However, as in toothed whales, there is no trace of a vomeronasal organ or nerve. The terminalis neuroblasts can already be distinguished from the olfactory material in the embryonic period, and they form compact masses medial and caudal to the developing olfactory bulb. As in most prenatal toothed whales, there are two large intrameningeal terminalis ganglia. These are connected with the telencephalic wall by central rootlets and with the septal mucosa by fiber bundles running through the level of the future cribriform plate. Clusters of terminalis neuroblasts also lie near the septal mucosa and along the peripheral terminalis fiber bundles. The functional implications of the olfactory and terminalis systems in whales are discussed.
对属于三种须鲸的八个胚胎和早期胎儿标本的组织进行了嗅觉和终末系统发育的研究。与齿鲸不同，须鲸，特别是在这些个体发育阶段，在鼻器官形态上的特化程度要低得多。鼻腔和外周嗅觉系统发育良好，没有退化的迹象。然而，与齿鲸一样，没有犁鼻器或神经的痕迹。终末成神经细胞在胚胎期就已经可以与嗅觉物质区分开来，它们在发育中的嗅球内侧和尾侧形成紧密的团块。与大多数产前齿鲸一样，有两个大的脑内终末神经节。它们通过中央小根与端脑壁相连，并通过穿过未来筛板水平的纤维束与鼻中隔黏膜相连。终末成神经细胞簇也位于鼻中隔黏膜附近并沿着外周终末纤维束排列。讨论了鲸类嗅觉和终末系统的功能意义。
