Experimental and Regenerative Neurosciences, School of Animal Biology, University of Western Australia, Perth, Australia.
Neuronal Rhythms in Movement Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan.
Sci Rep. 2018 Mar 5;8(1):4016. doi: 10.1038/s41598-018-22385-8.
Repetitive transcranial magnetic stimulation (rTMS) is commonly used to modulate cortical plasticity in clinical and non-clinical populations. Clinically, rTMS is delivered to targeted regions of the cortex at high intensities (>1 T). We have previously shown that even at low intensities, rTMS induces structural and molecular plasticity in the rodent cortex. To determine whether low intensity rTMS (LI-rTMS) alters behavioural performance, daily intermittent theta burst LI-rTMS (120 mT) or sham was delivered as a priming or consolidating stimulus to mice completing 10 consecutive days of skilled reaching training. Relative to sham, priming LI-rTMS (before each training session), increased skill accuracy (~9%) but did not alter the rate of learning over time. In contrast, consolidating LI-rTMS (after each training session), resulted in a small increase in the rate of learning (an additional ~1.6% each day) but did not alter the daily skill accuracy. Changes in behaviour with LI-rTMS were not accompanied with long lasting changes in brain-derived neurotrophic factor (BDNF) expression or in the expression of plasticity markers at excitatory and inhibitory synapses for either priming or consolidation groups. These results suggest that LI-rTMS can alter specific aspects of skilled motor learning in a manner dependent on the timing of intervention.
重复经颅磁刺激（rTMS）常用于调节临床和非临床人群的皮质可塑性。临床上，rTMS 以高强度（>1T）施加于皮质的靶向区域。我们先前的研究表明，即使在低强度下，rTMS 也会诱导啮齿动物皮质的结构和分子可塑性。为了确定低强度 rTMS（LI-rTMS）是否会改变行为表现，每天间歇性 theta 爆发 LI-rTMS（120mT）或假刺激被施加于完成 10 天连续熟练伸手训练的小鼠，作为启动或巩固刺激。与假刺激相比，启动 LI-rTMS（每次训练前）增加了技能准确性（~9%），但并没有改变随时间推移的学习速度。相比之下，巩固 LI-rTMS（每次训练后）导致学习速度略有增加（每天额外增加约 1.6%），但并没有改变每日技能准确性。LI-rTMS 引起的行为变化没有伴随着脑源性神经营养因子（BDNF）表达或兴奋性和抑制性突触的可塑性标志物表达的持久变化，无论是启动还是巩固组。这些结果表明，LI-rTMS 可以改变熟练运动学习的特定方面，其方式取决于干预的时间。
