Zemlan F P, Behbehani M M, Beckstead R M
Brain Res. 1984 Feb 6;292(2):207-20. doi: 10.1016/0006-8993(84)90757-1.
The projections of the rostral medulla were studied using retrograde and orthograde transport techniques in the rat. The present horseradish peroxidase (HRP) studies indicate that the ventral portion of nucleus reticularis gigantocellularis (NGC) and nucleus reticularis magnocellularis (NMC) project to both rostral and caudal levels of the spinal cord, while dorsal NGC projects only to the rostral cord. A differential density distribution of labeled cells was observed, with the greatest density of NGC-spinal neurons located rostral to the level of the inferior olive; and the greatest density of NMC-spinal neurons located caudally. This differential density distribution, when coupled with microiontophoretic application of [3H]amino acids allowed relatively independent labeling of the adjacent NGC- and NMC-spinal systems. On the basis of the HRP and autoradiographic studies 3 separate regions were delineated: dorsal NGC, ventral NGC and NMC. Descending projections from NGC were observed to the lateral vestibular nucleus, facial nucleus, hypoglossal nucleus and nucleus cuneatus. At cervical levels NGC fibers projected through the ventral and ventrolateral columns. Terminal fields were observed in laminae VII, VIII and to a lesser extent in IX. Labeled NGC fibers became difficult to follow by thoracic levels, which is consistent with the present HRP results. A continuum of descending NGC projections was observed with dorsally located NGC neurons projecting bilaterally through the ventral columns, and ventrally located NGC cells projecting through the ipsilateral ventrolateral columns. Ascending projections from NGC to the motor nucleus of V, trochlear nucleus, oculomotor nucleus, Edinger-Westphal nucleus, the ventral aspect of the periaqueductal gray, the deep and intermediate layers of the superior colliculus, nucleus parafasicularis and centromedianus, the Fields of Forel and the dorsal and lateral hypothalamic nuclei were observed. Descending projections from NMC to the dorsal nucleus of the vagus, hypoglossal nucleus, nucleus commissuralis and intercalatus were observed. At cervical levels, fibers project through the ipsilateral lateral columns, particularly its dorsal aspect. Terminal fields are located ipsilaterally in laminae IV, V and VI, and bilaterally in VII, VIII and X. NMC projections continue through caudal levels of the spinal cord including a projection to the ipsilateral intermediolateral columns. Ascending NMC projections are limited to the ventral pontine reticular formation.(ABSTRACT TRUNCATED AT 400 WORDS)
利用逆行和顺行运输技术在大鼠中研究了延髓嘴侧的投射。目前的辣根过氧化物酶（HRP）研究表明，巨细胞网状核（NGC）腹侧部分和大细胞网状核（NMC）投射到脊髓的嘴侧和尾侧水平，而NGC背侧仅投射到脊髓嘴侧。观察到标记细胞的密度分布存在差异，NGC脊髓神经元的最大密度位于下橄榄水平嘴侧；NMC脊髓神经元的最大密度位于尾侧。这种密度差异分布，再结合[3H]氨基酸的微离子电泳应用，使得相邻的NGC和NMC脊髓系统能够相对独立地被标记。基于HRP和放射自显影研究，划分出3个不同区域：NGC背侧、NGC腹侧和NMC。观察到NGC有下行投射至外侧前庭核、面神经核、舌下神经核和楔束核。在颈髓水平，NGC纤维通过腹侧柱和腹外侧柱投射。终末场见于第VII、VIII层，在第IX层较少见。到胸髓水平时，标记的NGC纤维难以追踪，这与目前的HRP结果一致。观察到NGC有连续的下行投射，背侧的NGC神经元通过腹侧柱双侧投射，腹侧的NGC细胞通过同侧腹外侧柱投射。观察到NGC有上行投射至三叉神经运动核、滑车神经核、动眼神经核、动眼神经副核、导水管周围灰质腹侧、上丘深层和中层、束旁核和中央中核、Forel区以及下丘脑背侧和外侧核。观察到NMC有下行投射至迷走神经背核、舌下神经核、连合核和中间神经核。在颈髓水平，纤维通过同侧外侧柱投射，特别是其背侧。终末场同侧位于第IV、V层，双侧位于第VII、VIII和X层。NMC投射贯穿脊髓尾侧水平包括投射至同侧中间外侧柱。NMC的上行投射仅限于脑桥腹侧网状结构。（摘要截短于400词）
