Meredith G E
Department of Anatomy, Medical Faculty, Vrije Universiteit, Amsterdam, The Netherlands.
Acta Biol Hung. 1988;39(2-3):229-49.
In all vertebrates, eighth nerve fibres from the inner ear distribute to target nuclei situated in the dorsolateral wall of the rhombencephalon. In amniotes, primary auditory and vestibular nuclei are readily delineated in that acoustic nuclei lie dorsal and sometimes rostral to vestibular nuclei. Fishes and aquatic amphibians have, in addition to labyrinthine organs, hair cell receptors in the lateral line system. Eighth nerve and lateral line fibres from these sense organs project to the octavolateralis region of the rhombencephalon. In this region, the primary nuclei cannot be easily divided into functionally distinct units. However, modality-specific zones seem to be present for auditory as well as lateral line projections lie dorsal and sometimes rostral to those from vestibular organs. Projections from the primary auditory and vestibular nuclei to higher order centres follow pathways which are conservative in their architecture among vertebrates. Ascending auditory fibres project either directly or via relay nuclei to a large midbrain center, the torus semicircularis (inferior colliculus) and hence to the forebrain. In fishes and aquatic amphibians, the lateral line system also sends a projection to the midbrain and information from this system may be integrated with auditory input at that level. The organization of vestibulospinal and vestibulo-ocular pathways shows little variation throughout vertebrate phylogeny. The sense organs of the inner ear of all vertebrates and of the lateral line system of anamniotes receive an efferent innervation. In anamniotes and some reptiles, the efferent supply originates from a single nucleus (Octavolateralis Efferent Nucleus) while that of "higher" vertebrates arises from separate auditory and vestibular efferent nuclei. The biological significance of this innervation for all vertebrates is not yet understood. However, an important feature common to all is the association of the efferent system with the motor centres of the hindbrain.
在所有脊椎动物中，来自内耳的第八神经纤维分布到位于菱脑背外侧壁的靶核。在羊膜动物中，初级听觉和前庭核很容易区分，因为听觉核位于前庭核的背侧，有时也位于其前方。鱼类和水生两栖动物除了有内耳迷路器官外，侧线系统中还有毛细胞感受器。来自这些感觉器官的第八神经和侧线纤维投射到菱脑的八侧区。在这个区域，初级核不容易被轻易地划分为功能上不同的单元。然而，听觉以及侧线投射似乎存在模态特异性区域，它们位于来自前庭器官的投射的背侧，有时也位于其前方。从初级听觉和前庭核到更高级中枢的投射遵循在脊椎动物中其结构保守的通路。上行听觉纤维直接或通过中继核投射到一个大的中脑中心，即半规管隆凸（下丘），进而投射到前脑。在鱼类和水生两栖动物中，侧线系统也向中脑发送投射，并且来自该系统的信息可能在那个水平与听觉输入整合。前庭脊髓和前庭眼通路的组织在整个脊椎动物系统发育过程中变化很小。所有脊椎动物内耳的感觉器官以及无羊膜动物侧线系统都接受传出神经支配。在无羊膜动物和一些爬行动物中，传出神经供应来自单个核（八侧传出核），而“高等”脊椎动物的传出神经供应则来自单独的听觉和前庭传出核。这种神经支配对所有脊椎动物的生物学意义尚未被理解。然而，所有情况共有的一个重要特征是传出系统与后脑的运动中枢相关联。
