Webb Aubrey A, Muir Gillian D
Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Sask., Canada S7N 5B4.
Behav Brain Res. 2004 Nov 5;155(1):55-65. doi: 10.1016/j.bbr.2004.04.002.
The purpose of this study was to determine the importance of the pathways running in the ventrolateral spinal funiculus for overground locomotion in adult, freely behaving rats. Left-sided ventrolateral cervical spinal cord injury was performed in adult female Long-Evans rats. The behavioural abilities of these animals were analyzed at 2 days, and weekly for up to 5.5 weeks following spinal cord injury. Behavioural testing consisted of Von Frey filament testing, ladder walking, a paw usage task, and the assessment of ground reaction forces during unrestrained trotting. Animals with injury to the left ventrolateral cervical spinal cord did not develop enhanced sensitivity to pedal mechanical stimulation. At 2 days following injury, animals had impaired skilled locomotion as indicated by increased number of footslips during ladder walking. At 2 days, these animals also used both limbs together more often for support while rearing, while using the forelimb ipsilateral to the injury less than did uninjured animals. Ground reaction force determination revealed that animals tend to bear less weight on the forelimb and hindlimb ipsilateral to the spinal cord injury 2 days after injury. All animals recovered normal or near normal sensorimotor abilities although subtle asymmetries in ground reaction forces were detectable at 5.5 weeks following spinal cord injury. These results suggest that axons in the ventrolateral spinal funiculi contribute to limb movements during exploration and locomotion but their roles can be served by other pathways after ventrolateral spinal injury.
本研究的目的是确定在成年自由活动大鼠中，脊髓腹外侧索中的传导通路对地面行走的重要性。对成年雌性Long-Evans大鼠进行左侧颈脊髓腹外侧损伤。在脊髓损伤后2天以及之后长达5.5周的时间里每周对这些动物的行为能力进行分析。行为测试包括von Frey细丝测试、爬梯行走、爪子使用任务以及在自由小跑期间对地面反作用力的评估。左侧颈脊髓腹外侧损伤的动物对足部机械刺激并未表现出增强的敏感性。损伤后2天，动物的熟练运动能力受损，表现为爬梯行走时失足次数增加。在损伤后2天，这些动物在站立时也更频繁地同时使用双肢进行支撑，同时与未受伤的动物相比，它们较少使用损伤同侧的前肢。地面反作用力测定显示，损伤后2天，动物倾向于在脊髓损伤同侧的前肢和后肢上承受较小的重量。尽管在脊髓损伤后5.5周可检测到地面反作用力存在细微的不对称，但所有动物均恢复了正常或接近正常的感觉运动能力。这些结果表明，脊髓腹外侧索中的轴突在探索和行走过程中有助于肢体运动，但在腹外侧脊髓损伤后，其他传导通路可以发挥它们的作用。
