Accurate motor mapping in awake common marmosets using micro-electrocorticographical stimulation and stochastic threshold estimation
Accurate motor mapping in awake common marmosets using micro-electrocorticographical stimulation and stochastic threshold estimation
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DOI：
10.1088/1741-2552/aab307
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发表时间：
2018-06-01
影响因子：
4
通讯作者：
Ushiba, Junichi
中科院分区：
文献类型：
--
作者：
Kosugi, Akito;Takemi, Mitsuaki;Ushiba, Junichi
目标。运动地形图已被广泛用作运动技能和学习、皮质损伤、可塑性和功能恢复的指标。使用硬膜外电极的皮质刺激标测最近被用于动物研究。然而，几个技术限制仍然存在。硬膜外皮质刺激(ECS)标测的重测可靠性尚未得到详细检验。以前的许多研究通过肉眼检查来定义诱发运动和运动阈值，因此缺乏定量测量。可靠和定量的运动图对于阐明运动皮质重组的机制是重要的。本研究的目的是根据运动诱发电位和长期植入的微型皮层脑电(MU-ECoG)电极阵列随机估计的运动阈值，对常见绒猴的运动表征进行可靠的ECS标测。接近。在清醒条件下，用植入的Mu-ECoG电极阵列对3只成年普通恒河猴进行了ECS。上肢肌肉植入肌电电极记录运动诱发电位。运动阈值由改进的最大似然阈值搜索算法计算，该算法与绒猴的记录数据相匹配。此外，计算机仿真证实了该算法的可靠性。主要结果。计算机仿真表明，改进的最大似然阈值搜索算法能够以可接受的精度估计运动阈值。活体ECS标测显示，关于皮质前肢运动表征的兴奋性和位置，重测可靠性很高。意义重大。使用植入的Mu ECoG电极阵列和改进的运动阈值搜索算法，我们能够利用ECS系统在普通绒猴上实现可靠的运动标测。
Objective. Motor map has been widely used as an indicator of motor skills and learning, cortical injury, plasticity, and functional recovery. Cortical stimulation mapping using epidural electrodes is recently adopted for animal studies. However, several technical limitations still remain. Test-retest reliability of epidural cortical stimulation (ECS) mapping has not been examined in detail. Many previous studies defined evoked movements and motor thresholds by visual inspection, and thus, lacked quantitative measurements. A reliable and quantitative motor map is important to elucidate the mechanisms of motor cortical reorganization. The objective of the current study was to perform reliable ECS mapping of motor representations based on the motor thresholds, which were stochastically estimated by motor evoked potentials and chronically implanted micro-electrocorticographical (mu ECoG) electrode arrays, in common marmosets. Approach. ECS was applied using the implanted mu ECoG electrode arrays in three adult common marmosets under awake conditions. Motor evoked potentials were recorded through electromyographical electrodes implanted in upper limb muscles. The motor threshold was calculated through a modified maximum likelihood threshold-hunting algorithm fitted with the recorded data from marmosets. Further, a computer simulation confirmed reliability of the algorithm. Main results. Computer simulation suggested that the modified maximum likelihood threshold-hunting algorithm enabled to estimate motor threshold with acceptable precision. In vivo ECS mapping showed high test-retest reliability with respect to the excitability and location of the cortical forelimb motor representations. Significance. Using implanted mu ECoG electrode arrays and a modified motor thresholdhunting algorithm, we were able to achieve reliable motor mapping in common marmosets with the ECS system.