AFFERENT CONNECTIONS OF THE ROSTRAL MEDULLA OF THE CAT - A NEURAL SUBSTRATE FOR MIDBRAIN-MEDULLARY INTERACTIONS IN THE MODULATION OF PAIN
AFFERENT CONNECTIONS OF THE ROSTRAL MEDULLA OF THE CAT - A NEURAL SUBSTRATE FOR MIDBRAIN-MEDULLARY INTERACTIONS IN THE MODULATION OF PAIN
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DOI：
10.1002/cne.902010211
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发表时间：
1981-01-01
影响因子：
2.5
通讯作者：
BASBAUM, AI
中科院分区：
文献类型：
--
作者：
ABOLS, IA;BASBAUM, AI
为研究猫延髓头端的结构及其在痛觉控制中的作用，观察了中缝大核（NRM）、外侧网状大细胞核（Rmc）和背侧网状大细胞核（Rgc）的传入联系。将HRP [辣根过氧化物酶]离子导入3个区域;绘制脑干和脊髓中逆行标记神经元的分布。虽然Rgc和NRM/Rmc的传入来源存在显著差异，但NRM和Rmc之间几乎没有区别。主要的脊髓投射是RGC;注射到RMC后记录的标记神经元较少。3个区域均接受来自延髓和脑桥网状结构内广泛区域的信息输入。最显着的差异，在分布的逆行标记的神经元被发现在中脑。向NRM和RMC的主要投射来自中脑导水管周围灰质（PAG）和邻近的楔状核。标记细胞集中在背侧和外侧PAG;很少被发现在腹外侧PAG。Rgc从PAG接收很少的传入; Rgc注射后，许多细胞记录在对侧顶盖的深层。没有一个注射部位产生显着标记的儿茶酚胺丰富的背外侧脑桥被盖或中缝背核。PAG投射到NRM/RMC的显著性的证明为以下假设提供了解剖学证据：阿片和刺激产生的镇痛涉及从PAG到NRM和RMC的神经元的连接，这反过来又抑制脊髓伤害性感受器。
To study the organization of the rostral medulla of the cat and its contribution to pain control mechanisms, the afferent connections of the midline nucleus raphe magnus (NRM), the laterally located nucleus reticularis magnocellularis (Rmc) and the nucleus reticularis gigantocellularis (Rgc) located dorsal to Rmc were studied. Iontophoretic injections of HRP [horseradish peroxidase] were made into the 3 regions; the distribution of retrogradely labeled neurons in brainstem and spinal cord was mapped. While significant differences characterize the source of afferents to Rgc and NRM/Rmc, there is little to distinguish that between NRM and Rmc. The predominant spinal projection is to Rgc; fewer labeled neurons were recorded after injections into Rmc. No significant direct spinal projection to NRM was found. All 3 regions receive input from widespread areas within the medullary and pontine reticular formation. The most pronounced differences in the distribution of retrogradely labeled neurons were found in the midbrain. The major projection to both NRM and Rmc derives from the periaqueductal gray (PAG) and from the adjacent nucleus cuneiformis. Labeled cells are concentrated in the dorsal and lateral PAG; few are found in the ventrolateral PAG. Rgc receives few afferents from the PAG; after Rgc injections, many cells were recorded in the deep layers of the contralateral tectum. None of the injection sites produced significant labeling of the catecholamine-rich dorsolateral pontine tegmentum or of the nucleus raphe dorsalis. The demonstration of significant PAG projections to NRM/Rmc provides anatomical evidence for the hypothesis that opiate- and stimulation-produced analgesia involves connections from PAG to neurons of NRM and Rmc which, in turn, inhibit spinal nociceptors.