Measurement of the neural activation potential of rat cerebral cortex using functional optical reflection tomography

功能性光学反射断层扫描测量大鼠大脑皮层神经激活电位

基本信息

批准号：
13480293
负责人：
HARUNA Masamitsu
金额：
$ 5.95万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2002
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-13480293/
关键词：
Functional reflection optical tomography (f-ORT)Coherence gate (OCT)Neural activation potential Measurement of refractive index of biological tissue Analysis of brain function

项目摘要

Our research target is proposal and demonstration of a novel functional optical reflection tomography (f-ORT). This unique technique is used for measurement of spatial and temporal distribution of neural activation potential of the cerebral cortex of rats, showing that the f-ORT is effective for brain neurology.(1) A SLD is used as the light source of the existing optical coherence tomography (OCT); however, the coherence length of SLD is 10 to 20 μm which is insufficient for detection of neural activation potential. In order for the detection, the SLD was replaced by a mode-locked Ti:sapphire laser which supplied the pulsewidth as short as lOfs. This laser can provide us OCT with the spatial resolution of 3 μm after proper compensation of chromatic dispersion of the interferometer.(2) In order to the high-resolution OCX described above, we developed the 1,3-μm OCT in which the imaging depth is improved to be 1.5mm or more. Subsequently, the desired optical reflection tomography was de … More veloped by combination of the coherence-gate optics and confocal optics.(3) The imaging data must be acquired as fast as possible in order to detect the neural activation potential in synchronization with the cardiac rate. Such a high-speed data acquisition can be realized by non-mechanical optical-delay scanning. In the f-ORT, the optical-delay scanning is performed by PZT fiber phase modulators, as a result, more than 50 optical-delay scans per second were obtained. All the raster scan signals are summed up to improve drastically the signal-to-noise ratio.(4) In the preliminary experiment, a refractive index change was detected by the f-ORT when a sound stimulus was applied to a rat. The index change may correspond to the neural activation potential due to a sound stimulus. A remarkable change of the optical reflection signal was detected in a 100-μm deep area 20s after application of the sound stimulus. On the basis of research results, as mentioned above, we have been developing the f-ORT for brain neurology. Less

我们的研究目标是提出并演示一种新型功能性光学反射断层扫描（f-ORT），这种独特的技术用于测量大鼠大脑皮层神经激活电位的空间和时间分布，表明 f-ORT 是有效的。 (1)现有光学相干断层扫描(OCT)采用SLD作为光源，但SLD的相干长度为10～20μm，不足以检测神经激活电位。为了进行检测，SLD 被锁模钛蓝宝石激光器取代，该激光器提供短至 10fs 的脉冲宽度，在对干涉仪的色散进行适当补偿后，该激光器可为我们提供 3 μm 的空间分辨率。 (2) 为了实现上述高分辨率 OCX，我们开发了 1,3-μm OCT，其中成像深度提高到 1.5mm 或更大。随后，通过相干门光学器件和共焦光学器件的结合，开发出了所需的光学反射断层扫描。(3) 必须尽快采集成像数据，以便与心脏同步检测神经激活电位。这种高速数据采集可以通过非机械光延迟扫描来实现，在f-ORT中，光延迟扫描是通过PZT光纤相位调制器来实现的。每秒获得超过 50 次光延迟扫描，所有光栅扫描信号被汇总，显着提高了信噪比。(4) 在初步实验中，f-ORT 检测到折射率变化。对大鼠施加声音刺激，该指数变化可能对应于声音刺激引起的神经激活电位，在施加声音刺激20秒后，在100微米深的区域中检测到光学反射信号的显着变化。在在研究结果的基础上，如上所述，我们一直在开发用于脑神经病学的f-ORT。