Botulinum toxin A injection into the entopeduncular nucleus improves dynamic locomotory parameters in hemiparkinsonian rats

Parkinson’s disease is associated with hyperactivity of the subthalamic nucleus (STN), contributing to motor and gait disturbances. Although deep brain stimulation of the STN alleviates certain motor dysfunction, its specific effect on gait abnormalities remains controversial. This study investigated the long-term changes in locomotion following direct infusions of botulinum toxin-A into the globus pallidus internal segment (GPi) to suppress the flow of information from the STN to the GPi in a hemiparkinsonian rat model. Static and dynamic gait parameters were quantified using a CatWalk apparatus. Interestingly, botulinum toxin-A at 0.5 ng significantly reduced only the dynamic gait parameters of hemiparkinsonian rats at 1 week and 1 month post-infusion, while static gait parameters did not change. This study offers new insights into the complexity of basal ganglia in locomotor control and shows the potential of central infusion of botulinum toxin-A as a novel intervention in the study of experimental hemiparkinson’s disease.

帕金森病（Parkinson’s disease）与丘脑底核（subthalamic nucleus, STN）过度激活相关，该核团过度激活可引发运动及步态障碍。尽管对丘脑底核实施脑深部电刺激（deep brain stimulation）可缓解部分运动功能障碍，但其对步态异常的具体作用仍存在争议。本研究以偏侧帕金森病大鼠模型（hemiparkinsonian rat model）为对象，探究了直接向苍白球内侧部（globus pallidus internal segment, GPi）输注A型肉毒毒素（botulinum toxin-A）以阻断丘脑底核至苍白球内侧部的信息传递后，运动行为的长期变化。研究采用CatWalk步态分析系统（CatWalk apparatus）对静态与动态步态参数进行量化测定。值得注意的是，输注后1周及1个月时，0.5 ng的A型肉毒毒素仅可显著降低偏侧帕金森病大鼠的动态步态参数，而静态步态参数未发生明显改变。本研究为理解基底节在运动调控中的复杂性提供了新视角，并表明中枢输注A型肉毒毒素有望作为实验性偏侧帕金森病研究中的新型干预手段。