稳态快速谱光学功能映射

提出了一种新的大脑光学功能映射流程。流程设计任务为周期形式,且周期远小于血液动力学的有效时间跨度。在连续周期刺激下,皮层功能区响应进入稳态,信号表现为围绕稳态值的周期小幅振荡。利用谱分析工具提取体元序列的任务频率成分、综合谱的幅值和相位信息最终确定任务相关脑区。采用SD大鼠的后肢区(HP)作为模型,使用红光(605±10nm)作为照射源。此流程很好地消除了血管伪迹。分析发现,左右脑后肢区任务响应有先后关系。根据相位图讨论了局部微循环血液交换、动静脉网的血液交换等问题。通过实验发现了高频刺激下血管系统的共振现象。实验结果证明本映射流程是一种有价值的新型功能映射流程,相对传统方法能够得到更多的皮层神经活动时空信息。

Rapid Spectral Optical Functional Mapping in Stable State Space

A novel functional optical mapping procedure for brain is proposed, which is in a periodical mode and the period is much shorter than the duration of the homodynamic course. Under continuous-periodic stimulation, the neural response of cortical functional region enters a stable state. The mapping signals vibrate at the stimulation frequency round some level in state space, which can be detected by the spectral analyzing techniques, and the task related brain region can be determined by synthesizing the altitude and phase distribution of the spectrum. Hind-paw (HP) area of SD mouse with sciatic nerve stimulation is used as the neural model in the experiment, with red light with 605±10 nm wavelength for illumination. The vascular overspill phenomenon is weakened greatly, resulting in a reduction of pseudo-maps. The phase distribution indicates that response of contralateral HP area is temporally prior to that of ipsilateral HP area. The arterial-venous transit and local blood circulation are also discussed. It is found that when relatively high frequency stimulation is applied, the vessel net will resonate with the stimuli. The procedure presents more spatio-temporal information of cortical neural activation than traditional ones, and proves another valuable functional mapping technqiue.