BOLD Responses in Human Auditory Cortex Are More Closely Related to Transient MEG Responses Than to Sustained Ones
BOLD Responses in Human Auditory Cortex Are More Closely Related to Transient MEG Responses Than to Sustained Ones
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DOI：
10.1152/jn.01005.2009
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发表时间：
2010-04-01
影响因子：
2.5
通讯作者：
Melcher, Jennifer R.
中科院分区：
文献类型：
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作者：
Gutschalk, Alexander;Haemaelaeinen, Matti S.;Melcher, Jennifer R.
人类听觉皮层的BOLD反应与瞬态脑磁图反应的关系比与持续脑磁图反应的关系更密切。中国生物医学工程学报（自然科学版），32(1):481 - 481。首次发表于2010年1月27日；doi: 10.1152 / jn.01005.2009。血氧水平依赖功能磁共振成像（BOLD-fMRI）和脑磁图（MEG）信号都与突触后电位相耦合，尽管它们之间的关系尚不完全清楚。为了更好地理解BOLD-fMRI/MEG之间的关系，研究人员利用了听觉皮层产生的广泛的BOLD-fMRI和MEG反应。在同一受试者中使用相同的刺激对两种方式进行BOLD和MEG反应的测量。刺激，即24秒的咔嚓序列，占空比分别为2.5%、25%、72%和100%。对于2.5%的序列，BOLD反应在整个序列中都是升高的，而对于100%的序列，它在序列开始和偏移后达到峰值，并在两者之间表现出降低的升高。在更精细的MEG时间尺度上，2.5%的响应由包括N(1)m在内的一系列瞬态组成，而100%的瞬态只发生在序列开始和MEG信号持续升高的偏移处（持续场）。当瞬态和持续MEG信号的权重是持续MEG信号的8- 10倍时，单独估计瞬态和持续MEG信号对BOLD响应的贡献的模型最适合BOLD测量。研究结果表明，听觉皮层的BOLD反应与脑磁图信号背后的短暂而非持续的神经活动紧密相关。
Gutschalk A, Hamalainen MS, Melcher JR. BOLD responses in human auditory cortex are more closely related to transient MEG responses than to sustained ones. J Neurophysiol 103: 2015-2026, 2010. First published January 27, 2010; doi: 10.1152/jn.01005.2009. Blood oxygen level dependent-functional magnetic resonance imaging (BOLD-fMRI) and magnetoencephalographic (MEG) signals are both coupled to postsynaptic potentials, although their relationship is incompletely understood. Here, the wide range of BOLD-fMRI and MEG responses produced by auditory cortex was exploited to better understand the BOLD-fMRI/MEG relationship. Measurements of BOLD and MEG responses were made in the same subjects using the same stimuli for both modalities. The stimuli, 24-s sequences of click trains, had duty cycles of 2.5, 25, 72, and 100%. For the 2.5% sequence, the BOLD response was elevated throughout the sequence, whereas for 100%, it peaked after sequence onset and offset and showed a diminished elevation in between. On the finer timescale of MEG, responses at 2.5% consisted of a complex of transients, including N(1)m, to each click train of the sequence, whereas for 100% the only transients occurred at sequence onset and offset between which there was a sustained elevation in the MEG signal (a sustained field). A model that separately estimated the contributions of transient and sustained MEG signals to the BOLD response best fit BOLD measurements when the transient contribution was weighted 8- to 10-fold more than the sustained one. The findings suggest that BOLD responses in the auditory cortex are tightly coupled to the neural activity underlying transient, not sustained, MEG signals.