Corticospinal tract transection reduces H-reflex circadian rhythm in rats
Corticospinal tract transection reduces H-reflex circadian rhythm in rats
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DOI：
10.1016/s0006-8993(02)02702-6
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发表时间：
2002-06-28
期刊：
影响因子：
2.9
通讯作者：
Jakeman, LB
中科院分区：
文献类型：
--
作者：
Chen, XY;Chen, L;Jakeman, LB
在自由活动的大鼠和猴子中，H反射振幅显示出明显的昼夜变化，而不改变背景运动神经元的音调。在大鼠中，H反射在中午左右最大，在午夜左右最小。本研究评价了大鼠胸中段脊髓校准挫伤和胸中段横断特定脊髓通路对这种节律的影响。对照组33只，节律幅度平均为29.0（+/-2.6S.E.）% H反射的振幅T8-9处的挫伤破坏了53-88%的白色物质，显著降低了节律至H反射振幅的18.9（+/-2.4）%。横断同侧柱（包含红核脊髓束、前庭脊髓束和网状脊髓束）或双侧横断背柱上行束不影响节律振幅或相位。相反，双侧皮质脊髓主束的处理显著降低了心律至14.7（+/-6.6）%。这些结果表明，H-反射昼夜节律部分取决于从大脑的下行影响，这种影响是由主要的皮质脊髓束。(C)2002 Elsevier Science B. V.保留所有权利。
In freely moving rats and monkeys, H-reflex amplitude displays a marked circadian variation without change in background motoneuron tone. In rats, the H-reflex is largest around noon and smallest around midnight. The present study evaluated in rats the effects on this rhythm of calibrated contusions of mid-thoracic spinal cord and mid-thoracic transection of specific spinal cord pathways. In 33 control rats, rhythm amplitude averaged 29.0(+/-2.6 S.E.)% of H-reflex amplitude. Contusion injuries at T8-9 that destroyed 53-88% of the white matter significantly reduced the rhythm to 18.9(+/-2.4)% of H-reflex amplitude. Transection of the ipsilateral lateral column, which contains the rubrospinal, vestibulospinal, and reticulospinal tracts, or bilateral transection of the dorsal column ascending tract did not affect rhythm amplitude or phase. In contrast, bilateral transaction of the main corticospinal tract significantly reduced the rhythm to 14.7(+/-6.6)%. These results indicate that the H-reflex circadian rhythm depends in part on descending influence from the brain and that this influence is conveyed by the main corticospinal tract. (C) 2002 Elsevier Science B.V. All rights reserved.