THE INNER-EAR OF GYMNOPHIONE AMPHIBIANS AND ITS NERVE SUPPLY - A COMPARATIVE-STUDY OF REGRESSIVE EVENTS IN A COMPLEX SENSORY SYSTEM (AMPHIBIA, GYMNOPHIONA)
THE INNER-EAR OF GYMNOPHIONE AMPHIBIANS AND ITS NERVE SUPPLY - A COMPARATIVE-STUDY OF REGRESSIVE EVENTS IN A COMPLEX SENSORY SYSTEM (AMPHIBIA, GYMNOPHIONA)
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DOI：
10.1007/bf00312221
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发表时间：
1988-01-01
期刊：
影响因子：
1
通讯作者：
WAKE, MH
中科院分区：
文献类型：
--
作者：
FRITZSCH, B;WAKE, MH
为了了解两栖类和基底乳头的起源和变化，对所有6个裸腹类家族的代表内耳以及一个物种的个体发育系列进行了研究。两栖类的乳突与一些成年裸腹两栖类的忽略乳突非常接近。在个体发育过程中，两个上皮细胞在被椭圆囊孔的形成分开之前是粘附的。两种上皮细胞的神经纤维走在一起，两种上皮细胞在两栖动物（两栖乳头）和脊椎动物（乳头忽略）之间的大小和位置上表现出相当的变化。基于这些论点，我们提出，两栖类乳头是一个易位的一部分，两栖类特有的乳头忽略。在所有原始裸腹动物中都有，但在所有衍生裸腹动物中都失去了基底乳头。与无尾类动物相反，但与一些有尾目、无尾目和Latimeria相似，基底乳头部分位于基底膜上。由于在结构，拓扑结构和神经支配的相似性，基底乳头被认为是同源的Latimeria和四足动物。大多数两栖动物的基底乳头的结构差异，相比于那些的Alabotes和Latimeria，可能是由于不同的过程中的耳周系统和形成的基底乳头的凹部，而不是一个单独的进化，这上皮。除了失去了基底乳头，一些衍生的裸腹动物已经失去了lagena，大概是独立的，两栖动物的乳头是非常减少的唯一属没有镫骨（$colecomorphus）。由于未知的功能原因，在水生裸腹动物中，忽略乳突相对较大，而在一些完全陆生的裸腹动物中，忽略乳突几乎消失。内耳的退行性变化并不反映在第八神经投射模式的明显变化上。然而，有一个重排的细胞团在菱脑背板的衍生gymnophionans，这可能与侧线传入的部分或全部损失。我们建议，存在一个基底乳头是一个synapomorphy的四足动物和Latimeria，易位的乳头忽略有关的两栖动物的耳周管的独特的过程中，并在内耳的退行性变化有关的原始没有鼓室耳。
The inner ears of representatives of all six gymnophionan families, as well as an ontogenetic series of one species, were studied in order to understand the origin and changes of the amphibian and basilar papillae. The amphibian papilla is in close proximity to the papilla neglecta in some adult gymnophionans. During ontogeny, both epithelia are adherent before they are separated by the formation of the utriculosaccular foramen. The nerve fibers to both epithelia run together, and both epithelia show a comparable variation in size and position among amphibians (amphibian papilla) and among vertebrates (papilla neglecta). Based on these arguments we propose that the amphibian papilla is a translocation of a part of the papilla neglecta specific to amphibians. Present in all primitive gymnophionans, the basilar papilla is lost in all derived gymnophionans. In contrast to anurans, but similar to some urodeles, amniotes, and Latimeria, the basilar papilla rests partly on a basilar membrane. Because of similarities in structure, topology, and innervation, the basilar papilla is suggested to be homologous in Latimeria and tetrapods. The structural differences of most amphibian basilar papillae, compared to those of amniotes and Latimeria, may be due to the different course of the periotic system and the formation of a basilar papillar recess rather than to a separate evolution of this epithelium. In addition to loss of the basilar papilla, some derived gymnophionans have lost the lagena, presumably independently, and the amphibian papilla is extremely reduced in the only genus without a stapes ($colecomorphus). The papilla neglecta is, for unknown functional reasons, relatively large in aquatic gymnophionans, whereas it is almost lost in some thoroughly terrestrial gymnophionans. The regressive changes in the inner ear are not reflected in obvious changes in the pattern of eighth nerve projection. However, there is a rearrangement of cell masses in the rhombencephalic alar plate of derived gymnophionans, which may be related to the partial or complete loss of lateral line afferents. We propose that the presence of a basilar papilla is a synapomorphy of tetrapods and Latimeria, that the translocation of the papilla neglecta is related to the unique course of the amphibian periotic canal, and that regressive changes in the inner ear are related to the primitive absence of a tympanic ear.