DIFFERENTIAL SITES OF ORIGIN AND COLLATERALIZATION OF CORTICOSPINAL NEURONS IN THE RAT - A MULTIPLE FLUORESCENT RETROGRADE TRACER STUDY
DIFFERENTIAL SITES OF ORIGIN AND COLLATERALIZATION OF CORTICOSPINAL NEURONS IN THE RAT - A MULTIPLE FLUORESCENT RETROGRADE TRACER STUDY
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DOI：
10.1016/0006-8993(92)90427-b
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发表时间：
1992-03-13
期刊：
影响因子：
2.9
通讯作者：
BUXTON, DF
中科院分区：
文献类型：
--
作者：
AKINTUNDE, A;BUXTON, DF
用荧光金(FG)、碘化丙啶(PI)、坚蓝(FB)和Diamidino黄(DY)单侧注入大鼠的腰椎(FG)、胸中(PI)、颈椎膨大(FB)和颅颈(DY)脊髓灰质，观察大鼠皮质脊髓纤维的起源。大多数标记神经元位于V层注射的对侧，大小不等。这些细胞占据了两个不同的皮质区域：一个是吻部，另一个是更大的尾部。吻区的神经元仅向颈段投射轴突，而尾区的神经元向所有脊髓节段投射纤维。体视学上，投射到腰段的神经元大多位于内侧。在所有标记的皮质神经元中，98%以上只含有一种荧光示踪剂；然而，在单个组织切片中，这些单一标记神经元中的每一种都可以找到这4种示踪剂。少数双标神经元仅含颈部(DY+FB)或胸腰段(PI+FG)示踪剂。未见三重或四重标记细胞。因此，提出了皮质脊髓轴突分支终止于一个以上脊髓区域的形态证据，但这些侧支终止仅限于少数相邻的脊髓节段。
Cells of origin for corticospinal fibers in the rat were identified following retrograde transport of Fluoro-Gold (FG), Propidium iodide (PI), Fast blue (FB), and Diamidino yellow (DY) injected unilaterally into lumbar (FG), mid-thoracic (PI), cervical enlargement (FB), and cranial cervical (DY) spinal gray matter. Most labeled neurons were contralateral to injection in lamina V and ranged from small to very large. These cells occupied two distinct cortical regions: one rostral and the other larger and more caudal. Neurons of the rostral region projected axons solely to cervical spinal segments whereas neurons of the caudal region projected fibers to all spinal segments. Somatotopically, most neurons projecting to lumbar segments were most medial. More than 98% of all labeled cortical neurons contained only a single fluorescent tracer; however, within a single tissue section each of the 4 tracers could be found in these single labeled neurons. The few double labeled neurons contained only cervical (DY + FB) or thoracolumbar (PI + FG) tracers. No triple or quadruple labeled cells were seen. Hence morphological evidence is presented that corticospinal axons branch to terminate in more than one spinal region, but these collateral terminations are restricted to only a few adjacent spinal segments.