Hayward Gail, Mehta Mitul A, Harmer Catherine, Spinks Terry J, Grasby Paul M, Goodwin Guy M
University Department of Psychiatry, Warneford Hospital, Oxford, OX3 7JX, UK.
Eur J Neurosci. 2007 Apr;25(7):2224-33. doi: 10.1111/j.1460-9568.2007.05430.x.
Transcranial magnetic stimulation (TMS) using a double-cone coil over the medial frontal cortex has the potential to clarify the function of the anterior cingulate cortex (ACC) in cognition, emotion and mood disorders. Following demonstration of disruption of performance on psychological tasks closely linked to cingulate function using this TMS technique, the current study aimed to directly measure the regional distribution of physiological effects of stimulation in the brain with H2(15)O PET. Experiment 1 assessed the effect of increasing numbers of pulse trains of TMS on regional cerebral blood flow (rCBF). Experiment 2 assessed the capacity of medial frontal TMS to modulate brain activity associated with the Stroop task using medial parietal TMS as a control site of stimulation. SPM99 analyses, using the ACC as a region of interest, revealed clusters of increased rCBF during medial frontal TMS in Brodmann area 24 and reduced rCBF in more ventral ACC, the latter occurring in both experiments. In a whole-brain analysis, striking changes in rCBF were observed distal to the ACC following medial frontal TMS. Although TMS reliably affected Stroop task performance in early trials, there was no interaction between TMS and Stroop condition in rCBF. Our results suggest that medial frontal TMS using the double-cone coil can affect ACC activity. However, a number of more distal cortical areas were also affected in these experiments. These additional changes may reflect either 'downstream' effects of altered cingulate cortex activity or direct effects of the coil.
在内侧额叶皮质上方使用双锥线圈进行经颅磁刺激（TMS），有可能阐明前扣带回皮质（ACC）在认知、情感和情绪障碍中的功能。在使用这种TMS技术证明与扣带回功能密切相关的心理任务表现受到干扰之后，本研究旨在利用H2(15)O PET直接测量大脑中刺激的生理效应的区域分布。实验1评估了增加TMS脉冲序列数量对局部脑血流（rCBF）的影响。实验2以内侧顶叶TMS作为对照刺激部位，评估内侧额叶TMS调节与Stroop任务相关的大脑活动的能力。使用ACC作为感兴趣区域的SPM99分析显示，在内侧额叶TMS期间，Brodmann 24区的rCBF增加，而在更靠腹侧的ACC中rCBF减少，后者在两个实验中均出现。在全脑分析中，在内侧额叶TMS后，在ACC远端观察到rCBF的显著变化。尽管在早期试验中TMS可靠地影响了Stroop任务的表现，但在rCBF方面，TMS与Stroop条件之间没有相互作用。我们的结果表明，使用双锥线圈的内侧额叶TMS可以影响ACC的活动。然而，在这些实验中，一些更远端的皮质区域也受到了影响。这些额外的变化可能反映了扣带回皮质活动改变的“下游”效应或线圈的直接效应。
