Department of Anatomy and the Brain Health Research Centre, University of Otago, PO Box 913, Dunedin 9054, New Zealand.
School of Physical Education and the Brain Health Research Centre, University of Otago, PO Box 56, Dunedin 9054, New Zealand.
Exp Neurol. 2014 Nov;261:258-66. doi: 10.1016/j.expneurol.2014.05.023. Epub 2014 Jun 3.
Following a cerebral cortex injury such as stroke, excessive inhibition around the core of the injury is thought to reduce the potential for new motor learning. In part, this may be caused by an imbalance of interhemispheric inhibition (IHI); therefore, treatments that relieve the inhibitory drive from the healthy hemisphere to the peri-lesional area may enhance motor recovery. Theta burst stimulation delivered by transcranial magnetic stimulation has been tested as a means of normalizing IHI, but clinical results have been variable. Here we use a new rat model of synaptic IHI to demonstrate that electrical intracranial theta burst stimulation causes long-lasting changes in motor cortex excitability. Further, we show that contralateral intermittent theta burst stimulation (iTBS) blocks IHI via a mechanism involving cannabinoid receptors. Finally, we show that contralesional iTBS applied during recovery from cortical injury in rats improves the recovery of motor function. These findings suggest that theta burst stimulation delivered through implanted electrodes may be a promising avenue to explore for augmenting rehabilitation from brain injury.
在大脑皮质损伤（如中风）后，人们认为损伤核心周围的过度抑制会降低新的运动学习的可能性。部分原因可能是由于大脑两半球间抑制（IHI）的不平衡；因此，减轻来自健康半球至损伤周边区域的抑制驱动力的治疗方法可能会增强运动功能恢复。经颅磁刺激的θ爆发刺激已被测试作为一种使 IHI 正常化的方法，但临床结果各不相同。在这里，我们使用一种新的突触 IHI 大鼠模型来证明电颅内θ爆发刺激会导致运动皮层兴奋性的持久变化。此外，我们还表明，对侧间歇性θ爆发刺激（iTBS）通过涉及大麻素受体的机制阻断 IHI。最后，我们发现，在大鼠皮质损伤后的恢复期间施加对侧 iTBS 可改善运动功能的恢复。这些发现表明，通过植入电极传递的θ爆发刺激可能是探索增强脑损伤康复的有前途的途径。
