CELLS OF ORIGIN OF SPINOTHALAMIC TRACT PROJECTIONS TO THE MEDIAL AND LATERAL THALAMUS IN THE CAT
CELLS OF ORIGIN OF SPINOTHALAMIC TRACT PROJECTIONS TO THE MEDIAL AND LATERAL THALAMUS IN THE CAT
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DOI：
10.1002/cne.902890404
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发表时间：
1989-11-22
影响因子：
2.5
通讯作者：
KNIFFKI, KD
中科院分区：
文献类型：
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作者：
CRAIG, AD;LININGTON, AJ;KNIFFKI, KD
双荧光逆行标记法被用来检查脊髓丘脑束（STT）细胞的分布，项目的内侧和外侧丘脑在猫。注射的一种荧光示踪剂（固蓝或Diamidino黄）在整个外侧丘脑和注射的其他示踪剂在内侧丘脑的网站外推记录轨道坐标。生存时间连续延长（长达5周），以最大限度地标记在颈椎和腰骶脊髓。平均而言，在来自节段C5-7和L5-S2的连续切片中计数超过2，000个标记的对侧STT细胞。数量级为2的因子变异性可归因于个体动物之间的固有差异。用荧光示踪剂标记的细胞总数与对照病例中用辣根过氧化物酶标记的细胞总数相当，尽管两种方法产生的标记的层状分布之间存在显着差异。在丘脑前部注射以控制由于渗漏或通过纤维引起的标记，未产生实质性脊髓标记。荧光染料标记的STT细胞的层状分布是一致的;约一半（47%）位于I层，8%位于V层，5%位于VI层，20%位于VII层，20%位于VIII层。颈段STT细胞I层和V层的比例（分别为57%和12%）高于腰骶段（38%和6%）。因此，荧光示踪剂揭示的纤层I细胞的STT的主要贡献是惊人的。从内侧和外侧丘脑标记的STT细胞的比例随节段和层流位置以及注射位置而变化。在大多数情况下，大多数（62%）的STT细胞仅投射到内侧丘脑，25%仅投射到外侧丘脑，13%投射到两者。在板层I，VII和VIII中的STT细胞群体各自显示出这种共同的投影模式。相反，在板层V和VI的细胞主要投射到外侧丘脑。2倍的STT细胞在板I（19%）投射到内侧和外侧丘脑从其他板。在L5-6节段，V-VIII层STT细胞投射到外侧丘脑的比例更大，在S1-2节段，更多投射到内侧丘脑。I层和VII-VIII层的标记模式的变化与n的注射覆盖率有关。中下神经和中央外侧神经，分别最后，内侧和外侧突出的STT细胞差异位于板I内; STT细胞在板I的腹外侧方面仅投射到内侧丘脑和细胞在其背内侧方面一般投射到外侧丘脑。这些观察结果证实了以前的电生理学研究结果关于板层I STT细胞，并共同提供了强有力的证据，结构和功能的组织内的STT。
The double fluorescent retrograde labeling method was used to examined the distribution of spinothalamic tract (STT) cells that project to the medial and lateral thalamus in the cat. Injections of one fluorescent tracer (Fast Blue or Diamidino Yellow) were made throughout the lateral thalamus and injections of the other tracer were made in the medial thalamus at sites extrapolated from recording track coordinates. Survival times were successively extended (up to 5 weeks) in order to maximize labeling in both the cervical and lumbosacral spinal cord. On average, over 2,000 labeled contralateral STT cells were counted in serial sections from segments C5-7 and L5-S2. Numerical variability of the order of a factor of two was attributable to inherent differences between individual animals. The total number of cells labeled with fluorescent tracers was comparable to the number labeled with horseradish peroxidase in control cases, although there were significant differences between the laminar distributions of labeling produced by the two methods. Injections made anterior to the thalamus to control for labeling due to leakage or passing fibers did not produce substantial spinal labeling. The laminar distribution of fluorescent dye-labeled STT cells was consistent; about half (47%) were located in lamina I, 8% were in lamina V, 5% in lamina VI, 20% in lamina VII, and 20% in lamina VIII. The proportions of STT cells laminae I and V were higher in cervical segments (57% and 12%, respectively) than in lumbosacral segments (38% and 6%). The dominant contribution of lamina I cells to the STT thus revealed by the fluorescent tracers is striking. The proportions of STT cells labeled from the medial and the lateral thalamus varied with segmental and laminar location and with injection placement. The majority (62%) of STT cells in most cases projected only to the medial thalamus, 25% projected only to the lateral thalamus, and 13% projected to both. The STT cell populations in laminae I, VII, and VIII each displayed this common projection pattern. In contrast, cells in laminae V and VI projected predominantly to the lateral thalamus. Twice as many STT cells in lamina I (19%) projected to both the medial and the lateral thalamus as from other laminae. A greater proportion of laminae V-VIII STT cells in segments L5-6 projected to the lateral thalamus, and in S1-2, more projected to the medial thalamus. Variations in the pattern of labeling in lamina I and laminae VII-VIII were related to injection coverage of the n. submedius and the centrolateral n., respectively. Lastly, medially and laterally projecting STT cells were differentially located within lamina I; STT cells in the ventrolateral aspect of lamina I projected only to the medial thalamus and cells in its dorsomedial aspect in general projected to the lateral thalamus. These observations corroborate previous electrophysiological findings regarding lamina I STT cells and collectively provide strong evidence of structural and functional organization within the STT.