Functional MRI of brain activation by eye blinking.
Functional MRI of brain activation by eye blinking.
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DOI：
10.1006/exer.1999.0660
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发表时间：
1999-07
影响因子：
3.4
通讯作者：
Kazuo Tsubota;Kenneth K. Kwong;Tsung Yi Lee;Jiro Nakamura;Hong Ming Cheng
中科院分区：
文献类型：
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作者：
Kazuo Tsubota;Kenneth K. Kwong;Tsung Yi Lee;Jiro Nakamura;Hong Ming Cheng
功能磁共振成像(FMRI)被用来绘制控制眨眼的皮质区域。T2加权不对称自旋回波MRI(或BOLD-血氧水平依赖-MRI)用于检测局部血氧变化引起的变化。六名正常志愿者和两名干眼症患者(小于5 mm的Schirmer‘s试验)进入研究。实验方案包括三个周期的两步序列：(闭上眼睛)-(眨眼或眨眼抑制)。为了将光激活造成的污染降到最低，实验在黑暗的环境中进行，志愿者报告说在磁共振扫描过程中没有感觉到光。在所有8个案例中，正常的眨眼(大约每4秒一次)激活了眼眶前额叶皮质的区域，在某些情况下，视觉皮质包括视觉皮质的前部和初级视觉皮质。在严重干眼症患者，即使在局部麻醉去除由于角膜干燥引起的刺激之后，眨眼抑制也会强烈激活视皮层。眨眼的过程，特别是眨眼的速度，似乎是在眼眶前额叶皮质控制的。在黑暗和严重干眼的情况下，视觉皮质激活的意义仍然不清楚，尽管它可能与注意力和觉醒有关。
Functional magnetic resonance imaging (fMRI) was used to map cortical areas that control eye blinking. T2*-weighted asymmetric spin-echo MRI (or BOLD-blood oxygen level dependent-MRI) was used to detect changes caused by focal variations in blood oxygenation. Six normal volunteers and two cases of dry eye (less than 5-mm Schirmer's test) entered the study. The experimental scheme consisted of three cycles of a two-step sequence: (eyes closed)-(blink or blink inhibition). And to minimize contamination from photic activation, the experiments were carried out in a dark environment and the volunteers reported no light perception during the MR scans. In all eight cases, normal blinking (about one blink every 4 sec) activated areas in the orbitofrontal cortex and in some cases, the visual cortex including the anterior portion of the visual cortex and the primary visual cortex. In severe dry eye, blink-inhibition strongly activated the visual cortex even after irritation due to corneal desiccation was removed by topical anesthesia. The blinking process, especially the rate, appears to be controlled in the orbitofrontal cortex. The significance of visual cortex activation in the dark and in the case of severe dry eye still remains unclear; although it may be associated with attention and arousal.