Mayhew J, Hu D, Zheng Y, Askew S, Hou Y, Berwick J, Coffey P J, Brown N
Artificial Intelligence Vision Research Unit, University of Sheffield, United Kingdom.
Neuroimage. 1998 Jan;7(1):49-71. doi: 10.1006/nimg.1997.0311.
Sequences of images of the cortical surface can be processed to reveal information about the cortical microcirculation, regional cerebral blood flow (rCBF), and changes induced by neuronal activity. This study examined the use of different analysis methodologies on intrinsic optical images taken from rat sensory motor cortex and testes. Generalized linear model (GLM) analysis was used and compared with standard signal processing methods including principal component analysis. The GLM method has been used by Friston et al. (1994, Hum. Brain Map., 1: 214-220) in the analysis of functional magnetic resonance imagery to identify regions of focal activity. We investigated the use of this method to analyze video image data of the modulation of rCBF from rat cortex. The results revealed spatiotemporal variations in rCBF in response to stimulation within local regions of cortex. The advantage of the GLM method is that it augments ordinary signal processing methods with an estimate of statistical reliability. The use of different wavelengths of illumination reveals spatial structures with different temporal relationships. In image time series data collected under green and red illumination a phase difference was found in the low frequency approximately 0.1 Hz vasomotion oscillation. This phase difference occurred in data from both cortex and testes. A possible explanation of these differences is that the spectral absorption characteristics of the tissue reflect changes in the volume proportions of the different hemoglobin derivatives in interacting with the modulation of the volume of blood. It is suggested that the combination of these effects produces the phase differences we detect.
皮质表面的图像序列可以进行处理，以揭示有关皮质微循环、局部脑血流量（rCBF）以及神经元活动所诱发变化的信息。本研究考察了对取自大鼠感觉运动皮层和睾丸的内在光学图像使用不同分析方法的情况。使用了广义线性模型（GLM）分析，并与包括主成分分析在内的标准信号处理方法进行比较。Friston等人（1994年，《人类脑图谱》，1: 214 - 220）已将GLM方法用于功能性磁共振成像分析，以识别局灶性活动区域。我们研究了使用该方法分析大鼠皮层rCBF调制的视频图像数据。结果揭示了皮质局部区域内刺激响应时rCBF的时空变化。GLM方法的优势在于它通过统计可靠性估计增强了普通信号处理方法。使用不同波长的照明揭示了具有不同时间关系的空间结构。在绿色和红色照明下收集的图像时间序列数据中，在约0.1 Hz的低频血管运动振荡中发现了相位差。这种相位差在来自皮层和睾丸的数据中均出现。对这些差异的一种可能解释是，组织的光谱吸收特性反映了不同血红蛋白衍生物在与血容量调制相互作用时体积比例的变化。有人认为，这些效应的组合产生了我们检测到的相位差。
