Wake D B, Nishikawa K C, Dicke U, Roth G
Museum of Vertebrate Zoology, University of California, Berkeley 94720.
J Comp Neurol. 1988 Dec 8;278(2):195-208. doi: 10.1002/cne.902780204.
The distribution and cytoarchitecture of motor nuclei of the cervical spinal cord were studied by using HRP techniques (whole mounts and sections) in 22 species of salamanders (families Hynobiidae, Dicamptodontidae, Ambystomatidae, Salamandridae, and Plethodontidae) representing a wide variety of life histories and functional modes of feeding. The nucleus of the first spinal nerve extends from the level of, or slightly caudad to, the root of the tenth cranial nerve, almost to the ventral root of the second spinal nerve. Approximately one-half of this nucleus is situated in the brainstem. This anterior extension is longest in bolitoglossine plethodontids. The nucleus of the second spinal nerve extends from the root of the first spinal nerve to the dorsal root of the second spinal nerve. The nuclei of the first and second spinal nerves in all species except bolitoglossines have motor neurons arranged in two columns: a lateral one containing large spindle-shaped cells and a medial one containing pear-shaped or polygonal smaller cells. The primary dendrites of these lateral and medial cells are parallel and their arborization is relatively narrow. In contrast, bolitoglossines lack the lateral motor column. The nucleus of the first spinal nerve consists only of a medial band of pear-shaped and sometimes polygonal cells, and the nucleus of the second spinal nerve is a wider band of pear-shaped and polygonal cells which are always situated inside the periventricular gray matter. The arrangement of the somata in bolitoglossines is less organized and the primary dendrites are less parallel and have a broader arborization than in other salamanders. In all species, cells in the second spinal nucleus are arranged in a less orderly manner than those in the first. All salamanders studied possess a spinal accessory nerve whose motor neurons are located in the cervical spinal cord; the axons leave the brainstem with fibers of the vagus nerve. The rostrocaudal extent of this nucleus differs markedly among species. In bolitoglossines the nucleus is more or less restricted to the region of the nucleus of the second spinal nerve. In all other species studied, the accessory nucleus extends from the obex to the caudal end of the nucleus of the third spinal nerve. In the tribe Plethodontini the cytoarchitecture of the accessory nucleus is similar to that of the second spinal. In desmognathine and hemidactyliine plethodontids as well as in all nonplethodontid species studied the nucleus consists of pear-shaped and cone-shaped cells.(ABSTRACT TRUNCATED AT 400 WORDS)
运用辣根过氧化物酶技术（整装片和切片），对22种蝾螈（隐鳃鲵科、肥螈科、钝口螈科、蝾螈科和无肺螈科）的颈脊髓运动核的分布和细胞结构进行了研究，这些蝾螈代表了广泛的生活史和摄食功能模式。第一脊髓神经核从第十脑神经根部水平或稍靠尾侧处延伸，几乎到第二脊髓神经的腹根。该核约一半位于脑干。这种向前的延伸在无肺螈科的疣螈属中最长。第二脊髓神经核从第一脊髓神经根部延伸到第二脊髓神经的背根。除疣螈属外，所有物种的第一和第二脊髓神经核都有两列运动神经元：外侧一列包含大的梭形细胞，内侧一列包含梨形或多边形的较小细胞。这些外侧和内侧细胞的初级树突平行，其分支相对较窄。相比之下，疣螈属没有外侧运动柱。第一脊髓神经核仅由一条内侧带组成，包含梨形细胞，有时还有多边形细胞，第二脊髓神经核是一条较宽的带，由梨形和多边形细胞组成，这些细胞总是位于室周灰质内。疣螈属中细胞体的排列不太规则，初级树突不如其他蝾螈那样平行，分支也更宽。在所有物种中，第二脊髓核中的细胞排列比第一脊髓核中的细胞更无序。所有研究的蝾螈都有一条脊髓副神经，其运动神经元位于颈脊髓；轴突与迷走神经纤维一起离开脑干。该核在头尾方向上的范围在不同物种间差异显著。在疣螈属中，该核或多或少局限于第二脊髓神经核的区域。在所有其他研究的物种中，副神经核从闩延伸到第三脊髓神经核的尾端。在无肺螈族中，副神经核的细胞结构与第二脊髓神经核相似。在锯螈属和半趾螈属的无肺螈科以及所有研究的非无肺螈科物种中，该核由梨形和锥形细胞组成。（摘要截于400字）
