Carpenter M B, Cowie R J
Brain Res. 1985 Dec 9;358(1-2):249-63. doi: 10.1016/0006-8993(85)90969-2.
Transneuronal transport of [3H]proline, [3H]fucose, and [3H]leucine in various combinations from pledgets implanted in the ampulla of a single semicircular duct was studied in the squirrel monkey and arctic ground squirrel after long survival periods. Tritiated amino acids implanted in any single ampulla resulted in labeling of nearly all vestibular and auditory receptors, nearly all cells of the vestibular and spiral ganglia and central transport via nearly all root fibers of both nerves. Primary vestibular fibers were distributed to the vestibular nuclei (VN) and specific parts of the cerebellum in the pattern previously described. Transneuronal transport of [3H]proline by vestibular neurons was present in all known secondary pathways, except those projecting to thalamic nuclei. Observations were similar in both species, except for small differences in commissural vestibular projections. Major commissural transport was to all parts of the opposite medial vestibular nucleus (MVN) and to peripheral parts of the superior vestibular nucleus (SVN), but some transport was present in all contralateral VN, including ventral cell group y. Descending transneuronal transport was evident in vestibulospinal tract (VST) ipsilaterally and in the medial longitudinal fasciculus (MLF) bilaterally. Both [3H]proline and [3]fucose were transported transneuronally to the ipsilateral abducens nucleus (AN); with long survivals [3H]proline was transported peripherally via the ipsilateral abducens nerve root. Ascending transport in the MLF was bilateral, asymmetric and greatest contralaterally. Fibers entered the contralateral MLF near the AN and the lateral wing of the ipsilateral MLF rostral to most of the VN. Terminals in the trochlear nuclei (TN) were bilateral and greatest contralaterally. In the monkey terminals in ipsilateral oculomotor complex (OMC) were distributed uniformly in all subdivisions, except for the medial rectus subdivision (MRS), where terminals were more numerous. The greatest density of terminals was present contralaterally in the superior rectus subdivision (SRS) of the OMC; only sparse terminals were present in the MRS on that side. Transport in the ipsilateral abducens nerve roots in the monkey and the virtual absence of transport to the MRS of the contralateral OMC suggested transneuronal transport to abducens motor neurons, but not to internuclear neurons (AIN). The AIN project only to the MRS of the contralateral OMC and do not appear to receive vestibular input. Comparable observations were made in the AN, TN and OMC of the ground squirrel, although the representation of the extraocular muscles in the OMC is unknown.(ABSTRACT TRUNCATED AT 400 WORDS)
在松鼠猴和北极地松鼠中，研究了在单个半规管壶腹植入药棉后，[3H]脯氨酸、[3H]岩藻糖和[3H]亮氨酸以各种组合形式进行的跨神经元运输，观察期较长。植入任何单个壶腹的氚标记氨基酸几乎标记了所有前庭和听觉感受器、前庭和螺旋神经节的几乎所有细胞，并通过两条神经的几乎所有根纤维进行中枢运输。初级前庭纤维以前述模式分布到前庭核（VN）和小脑的特定部位。除了投射到丘脑核的那些通路外，前庭神经元对[3H]脯氨酸的跨神经元运输存在于所有已知的二级通路中。除了连合前庭投射存在微小差异外，两个物种的观察结果相似。主要的连合运输是到对侧内侧前庭核（MVN）的所有部位和上前庭核（SVN）的周边部位，但在所有对侧VN中都有一些运输，包括腹侧细胞群y。下行跨神经元运输在前庭脊髓束（VST）同侧和内侧纵束（MLF）双侧都很明显。[3H]脯氨酸和[3H]岩藻糖都跨神经元运输到同侧展神经核（AN）；存活时间较长时，[3H]脯氨酸通过同侧展神经根向周边运输。MLF中的上行运输是双侧的、不对称的，对侧最为明显。纤维在展神经核附近进入对侧MLF，在同侧MLF的外侧翼，位于大多数前庭核的前方。滑车神经核（TN）中的终末是双侧的，对侧最多。在猴子中，同侧动眼神经复合体（OMC）中的终末在所有亚区均匀分布，但在内直肌亚区（MRS）终末较多。终末密度最大的是对侧OMC的上直肌亚区（SRS）；该侧MRS中只有稀疏的终末。猴子同侧展神经根中的运输以及对侧OMC的MRS几乎没有运输，这表明跨神经元运输到展神经运动神经元，但没有运输到核间神经元（AIN）。AIN仅投射到对侧OMC的MRS，似乎不接受前庭输入。在北极地松鼠的展神经核、滑车神经核和动眼神经复合体中也有类似的观察结果，尽管动眼神经复合体中眼外肌的代表情况尚不清楚。（摘要截取自400字）
