Functional organization in the monkey frontal eye field particularly in the deep region of the anterior arcuate bank

在猴子中，弓状沟吻侧的皮质区域被称为额叶眼场(FEF)，因为眼球跳动是由电刺激引起的。本研究的目的是通过探索前弓状回底部来揭示FEF的确切范围，以及FEF中的刺激部位与所诱发的眼跳向量之间的关系。清醒的日本猴子坐在灵长类动物的椅子上，头部紧紧地固定着。将Elgiloy微电极按选择的方向通过硬脑膜插入脑内，并用该电极进行皮质内微刺激以激发眼跳。结果如下：1.FEF从主沟尾端向尾侧延伸至弓状沟底部，内侧宽7~10 mm。2.当刺激部位沿FEF的放射状细胞阵列移动时，无论刺激部位的皮质层是什么，诱发的眼跳向量都保持不变。然而，随着刺激点沿皮质表面的移位，向量逐渐改变。眼跳幅度在30ﾟ以下，方向与刺激FEF相反，垂直分量有不同程度的改变。3.当刺激部位由FEF内侧移至FEF外侧时，眼跳幅度逐渐增大。相反，随着刺激部位的旋转尾部移动，眼跳方向依次改变。通常，相同的扫视方向在FEF的较远区域被发现两次或更多。基于这些发现，我们讨论了FEF在动物眼球跳动中的作用。

In a monkey, the cortical region rostral to the arcuate sulcus is called the frontal eye field (FEF), because saccadic eye movements are elicited by electrical stimulation. Purposes of this study are to reveal the exact extent of the FEF by exploring up to the bottom of the anterior arcuate bank, and to show the relationship between the stimulating site in the FEF and elicited saccade vector. Awake Japanese monkeys were sat in primate chairs with their heads tightly fixed. An Elgiloy microelectrode was inserted into the brain through the dura with a selected direction of the electrode, and intracortical electrical microstimulation was done with the electrode to elicite saccades. Results were as follows: 1. The FEF extended rostrocaudally from the caudal end of the principal sulcus to the bottom of the arcuate sulcus, with a mediolateral width of 7-10 mm. 2. When the stimulating site was moved along a radial cell array of the FEF, vector of the elicited saccade remained constant irrespective of the cortical layer of the stimulating site. However, the vector changed gradually with a shift of the stimulating sites along the cortical surface. The saccade amplitude was below 30ﾟ and its direction was contralateral to the stimulating FEF with varying degrees of the vertical component. 3. Amplitude of the saccade is increased gradually, when the stimulating site was moved from medial to lateral FEF. In contrast, saccade direction changed successively with a rostrocaudal shift of the stimulating site. Usually the same saccade direction was found twice or more in distant areas in the FEF. Based on the findings, we discussed the role of the FEF on saccadic eye movements of the animal.