Mediolateral and dorsoventral projection patterns of cutaneous afferents within transverse planes of the mouse spinal dorsal horn
Mediolateral and dorsoventral projection patterns of cutaneous afferents within transverse planes of the mouse spinal dorsal horn
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DOI：
10.1002/cne.24593
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发表时间：
2019-04-01
影响因子：
2.5
通讯作者：
Sakurai, Masaki
中科院分区：
文献类型：
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作者：
Odagaki, Kaoru;Kameda, Hiroshi;Sakurai, Masaki
皮内注射 AlexaFluor 488 缀合和/或 594 缀合的霍乱毒素 B 亚基 (CTB) 后，研究了小鼠前肢和肩部皮肤传入神经在脊髓背角的中央投射模式。根据皮节，以下八个皮肤区域被认为受第六至第八颈脊神经根的脊神经支配：肩背、臂、前臂近端、前臂远端、手、第二和第三指的掌面和手掌。肩部和前臂背侧传入神经的终止区较窄，沿背腹方向分布，在第六至第八颈背角内从外侧到内侧依次排列。相比之下，第二和第三指掌面的终止区域大部分重叠。我们还将 CTB 注射到后肢和骨盆区域的背表面。人们认为那里的皮肤区域受到第三至第五腰椎脊神经根的神经支配。观察到的腰椎背角的投影模式与颈部模式相似。注射 CTB 和麦芽凝集素缀合辣根过氧化物酶 (WGA-HRP) 的混合物（被认为分别标记 A beta 和 A delta/C 纤维），显示出 CTB 和 WGA-HRP 标记传入神经的分离终止区域。此外，终止区域的对齐是在背腹方向。这些结果表明，脊髓背角内存在精细的躯体（中外侧轴）和形态特异性（背腹轴）组织。
The central projection patterns of cutaneous afferents from the forelimb and shoulder of mice were studied in the spinal dorsal horn after intracutaneous injection of AlexaFluor 488-conjugated and/or 594-conjugated cholera toxin subunit B (CTB). Based on their dermatomes, the following eight skin regions are thought to be innervated by spinal nerves from the sixth to eighth cervical spinal nerve roots: the dorsal surface of the shoulder, brachium, proximal forearm, distal forearm, hand, palmar surface of the second and third digits, and palm. The termination areas of afferents from the dorsal surface of the shoulder and forearm were narrow, distributed in a dorsoventral direction, and aligned in order from lateral to medial within the sixth to eighth cervical dorsal horns. By contrast, the termination areas of the palmar surface of the second and third digits largely overlapped. We also injected CTB into the dorsal surface of the hindlimb and pelvic regions. Skin regions there are thought to be innervated by nerves from the third to fifth lumbar spinal nerve roots. The observed projection patterns in the lumbar dorsal horn were similar to the cervical patterns. Injection of a mixture of CTB and wheat-germ agglutinin-conjugated horseradish peroxidase (WGA-HRP), which are thought to label A beta and A delta/C fibers, respectively, showed segregated termination areas of CTB- and WGA-HRP-labeled afferents. Moreover, alignment of the termination areas was in the dorsoventral direction. These results suggest there is fine somatotopic (mediolateral axis) and modality-specific (dorsoventral axis) organization within the spinal dorsal horn.