The effect of age on the homotopic motor cortical long-term potentiation-like effect induced by quadripulse stimulation
The effect of age on the homotopic motor cortical long-term potentiation-like effect induced by quadripulse stimulation
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DOI：
10.1007/s00221-017-4953-0
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发表时间：
2017-07-01
影响因子：
2
通讯作者：
Ugawa, Yoshikazu
中科院分区：
文献类型：
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作者：
Hanajima, Ritsuko;Tanaka, Nobuyuki;Ugawa, Yoshikazu
在动物实验中，许多先前的论文已经证明了可塑性随着年龄的增长而降低。这个问题可以在人类身上研究，因为几种非侵入性脑刺激技术可以在人脑中诱导突触可塑性。我们研究了个体年龄对四脉冲磁刺激(QPS)诱发的长时程增强(LTP)样效应响应率的影响。受试者为107名健康志愿者：53名老年受试者(平均+/-SD65.0+/-1.5岁)和54名年轻受试者(平均37.2+/-8.7岁)。以5ms脉冲间隔(QPS5)对初级运动皮质(M1)进行四脉冲刺激。分别于QPS前、QPS后5个时间点进行运动诱发电位(MEP)检测，最长时间为25min。在每个参与者中，量化平均MEP幅度(大小)比率。我们首先通过比较大小比为1.0来简单地将参与者分类为响应者和无响应者，以与先前的研究保持一致，然后通过将大小比与假条件下MEP大小比率的平均值和标准差进行比较来进行更详细的分析，以进行更详细的分析。与年轻组相比，老年组中QPS5引起的LTP样效应的程度明显较小。此外，与年轻组(分别为80%和76%)相比，老年组的应答者和显著应答者的比率(分别为58%和47%)更低。参与者的年龄显著影响了QPS5诱导的LTP样效应，这表明大脑的可塑性随着年龄的增长而降低。
The reduction of plasticity with age has been shown by many previous papers in animal experiments. This issue can be studied in humans because several non-invasive brain stimulation techniques induce synaptic plasticity in the human brain. We investigated the influence of individuals' age on the responder rate of the long-term potentiation (LTP)-like effect induced by quadripulse magnetic stimulation (QPS). The participants were 107 healthy volunteers: 53 older participants (Mean +/- SD 65.0 +/- 1.5 years) and 54 younger participants (37.2 +/- 8.7). The quadripulse stimulation with 5-ms inter-pulse interval (QPS5) was applied over the primary motor cortex (M1). We measured motor evoked potentials (MEPs) before QPS, and at five time points after QPS for up to 25 min. In each participant, average MEP amplitude (size) ratios were quantified. We first classified participants as responders and non-responders simply by comparing the size ratio with 1.0 for consistency with previous studies, then as "significant responders", "non-responders", and "opposite responders" for more detailed analysis by comparing the size ratio with the mean and standard deviation of the MEP size ratios of the sham condition. The degree of LTP-like effects induced by QPS5 was significantly smaller in the older group compared to the younger group. Also, the rates of responders and significant responders were lower in the older group (58 and 47%, respectively) compared to the younger group (80 and 76%, respectively). The age of the participants significantly affected the LTP-like effect induced by QPS5, which suggests that brain plasticity decreases with age.