We applied repetitive transcranial magnetic stimulation (rTMS) to the unilateral hemisphere of rat brain, by placing a 25-mm figure-8 coil 1 cm lateral to the vertex on the biauricular line and angulating the coil by 45°. An in-house water cooling system was used for rTMS for more than 20 min.
Previous rodent models of repetitive transcranial magnetic stimulation (rTMS) adopted whole-brain stimulation instead of unilateral hemispheric rTMS, which is unlike the protocols used for human subjects. We report a successful application of rTMS to the unilateral hemisphere of rat brain. The rTMS was delivered with a low-frequency (1 Hz), high-frequency (20 Hz), or sham stimulation protocol to one side of the brain by using a small 25-mm figure-8 coil. We placed the center of the coil 1 cm lateral to the vertex on the biauricular line and angulated the coil 45° to the ground to minimize a potential direct effect of rTMS on the contralateral cortex. We also used an in-house water cooling system to enable repetitive magnetic stimulation for more than 20 min, even at a 20-Hz stimulation frequency. Increases in the transcriptions of immediate early genes (Arc, Junb, and Egr2) were greater after rTMS than after sham stimulation. After 5 consecutive days of 20-min 1-Hz rTMS, bdnf mRNA expression was significantly higher in stimulated cortex than in contralateral side. The model presented herein will elucidate the molecular mechanisms of rTMS by allowing analysis of the inter-hemispheric difference in its effect.
重复经颅磁刺激(rTMS治疗),用于非侵入性脑刺激和神经调节的工具,已经在各种病症的治疗被应用于如中枢性疼痛1,2,抑郁心情 ,偏头痛4,甚至中风5-7。通过线圈快速变化的电流在磁头诱导对大脑皮层和所得神经元激活电场。大脑皮层的兴奋性可以通过磁刺激,从而可以持续超过30分钟的刺激终止后进行调制。
后效应的磁刺激的建议的机制包括长时程增强/抑郁症样作用8,在离子平衡9短暂移位,和代谢改变10。此外,迪拉扎罗等 。表明,间歇THETA突发刺激影响兴奋性突触输入到锥体束神经元,无论是在刺激与对侧大脑半球11。
显著的限制,但是,已经从台上证据转化为临床情况阻碍了研究人员。首先,在以前的动物研究中,磁刺激用于全脑刺激12。全脑刺激是从人类研究9所使用的协议完全不同。另一个问题是与刺激的持续时间有关。这至少部分归因于一个事实,即一个有效的冷却系统是在过去的小线圈不可用。
近年来,精液文章已经发表建议用于克服对小动物大脑中的磁刺激实验这些困难的方式。由这些动物模型中,据透露,在大鼠脑还示出了响应于低频磁刺激13相似皮质兴奋的变化作为人类。更重要的是,经颅磁刺激的细胞和分子机制越来越蓓NG使用经颅磁刺激的动物模型研究。一个典型的例子是,一个独特的类型抑制中间神经元的被称为是间歇THETA爆发刺激14最为敏感。经颅磁刺激的啮齿类动物模型,因此,探索对颅磁刺激引起的变化的分子基础备受追捧的问题提供了新的机遇。如果经颅磁刺激的小动物模型可以更加实验室使用,它可能会大大加快,并在这方面加强研究。
我们现在描述如何将磁刺激应用于大鼠脑,将先前的工作15的延伸的单方面半球。刺激诱导的变化通过使用微正电子发射断层扫描(PET)和mRNA微阵列来研究在受刺激大脑皮质的rTMS引起的变化进行评价。
这项研究的主要目的是介绍单边rTMS治疗的动物模型。虽然单边刺激是人类颅磁刺激研究的最根本的特征之一,许多研究都没有小动物采用。然而,罗滕贝格等人 15记录,使用具有20毫米的外瓣直径的8字形线圈100%MT的刺激对侧的MEP,而刺激112.5%和133.3%的MT产生同侧以及对侧的MEP。这可能是因为大感应电场可影响对侧半球。因此,我们的研究是此以前的工作15,24的延伸?…
The authors have nothing to disclose.
This work was supported by the Korea Research Foundation Grant funded by the Korean Government (KRF-2008-313-E00458). The authors thank Jin-Joo Lee for the technical assistance.
Homeothermic blanket with a rectal probe | Harvard apparatus | 507222F | |
Isoflurane (Forane sol.) | Choongwae | ||
Propofol (Provive Inj. 1% 20ml) | Claris Lifesciences | ||
Repetitive magnetic stimulator (Magstim Rapid2) | Magstim Company Ltd | ||
25 mm figure-of-8 coil | Magstim Company Ltd | 1165-00 | |
PET-CT | GE Healthcare | ||
QIAzol Lysis Reagent | Qiagen | (US Patent No. 5,346,994) | |
RNeasy Lipid Tissue Mini Kit | Qiagen | 74804 | |
RNeasy Mini Spin Columns | Qiagen | (Mat No. 1011708) | |
Agilent 2100 Bioanalyzer | Agilent Technologies | ||
Ambion Illumina RNA amplification kit | Ambion | ||
Nanodrop Spectrophotometer | NanoDrop | ND-1000 | |
Illumina RatRef-12 Expression BeadChip | Illumina, Inc. | ||
Amersham fluorolink streptavidin-Cy3 | GE Healthcare Bio-Sciences |