Chaouch A, Menetrey D, Binder D, Besson J M
J Comp Neurol. 1983 Mar 1;214(3):309-20. doi: 10.1002/cne.902140308.
An anatomical technique based on the retrograde transport of horseradish peroxidase (HRP) was used to investigate the projections of spinal cord neurons to the reticular formations in the rat. Both large and restricted injections were staggered all along the bulbar and pontine levels, involving the nucleus gigantocellularis, the nuclei reticularis pontis, pars oralis and caudalis and in some cases the nucleus raphé magnus. Labeled cells were constantly encountered in the reticular part of the neck of the dorsal horn throughout the whole length of the cord, mainly contralateral to the central core of the injection site. This area was taken as the equivalent of lamina V in the cat. Other labeled cells were observed in the medial parts of the intermediate and ventral horns, in areas considered similar to laminae VII and VIII in the cat. The two most rostral cervical segments were characterized by an additional bilateral projection originating from the dorsolateral part of ventral horns. Thus, this study is a clear confirmation that the bulbopontine reticular formations constitute a target for various somatosensory inputs originating in spinal cord. It demonstrates that the medial spinoreticular tract (mSRT) differs from the other main ascending tracts by the absence of projections from (1) superficial layers and nucleus of the dorsolateral funiculus contrary to the spinomesencephalic tract; (2) ventromedial zone of the lumbar dorsal horn unlike the spinothalamic tract; (3) the neck of the dorsal horn in its medial portion contrary to the spinoreticular component reaching the lateral reticular nucleus; and (4) central cervical nucleus and Clarke's columns, unlike the spinocerebellar tracts. The difficulty in demonstrating retrograde labeling from discrete injections could result from the fact that mSRT neurons have sparsely ramified collaterals on their terminal zones.
采用基于辣根过氧化物酶（HRP）逆行运输的解剖学技术，研究大鼠脊髓神经元向网状结构的投射。在延髓和脑桥水平全程交错进行大剂量和局限性注射，涉及巨细胞网状核、脑桥网状核、嘴侧部和尾侧部，在某些情况下还涉及中缝大核。在脊髓全长背角颈部的网状部分持续发现标记细胞，主要位于注射部位中央核心的对侧。该区域被视为猫的V层的对应区域。在中间角和腹角的内侧部分也观察到其他标记细胞，这些区域被认为类似于猫的VII层和VIII层。最头端的两个颈段的特征是，腹角背外侧部分有额外的双侧投射。因此，本研究明确证实，延髓脑桥网状结构是脊髓起源的各种躯体感觉输入的靶标。它表明，内侧脊髓网状束（mSRT）与其他主要上行束不同，表现为：（1）与脊髓中脑束相反，背外侧索浅层和核无投射；（2）与脊髓丘脑束不同，腰髓背角腹内侧区无投射；（3）与到达外侧网状核的脊髓网状成分相反，背角颈部内侧部分无投射；（4）与脊髓小脑束不同，中央颈核和克拉克柱无投射。难以从离散注射中显示逆行标记，可能是因为mSRT神经元在其终末区有稀疏分支的侧支。
