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Functional Brain Imaging Summary

Decent Essays
A recently published article discussed optical techniques that exist for functional brain imaging (Liao et. al., 2013). The processes in the brain utilize several mechanisms that primarily regulate blood flow within the brain. The variances of blood flow are closely related with neural activity. Imaging techniques utilize these processes to analyze functional brain activity and produce reliable results. However, different optical techniques will analyze different neuronal activity in different parts of the brain. 2-photon laser scanning microscopy(TPLSM) is utilized to observe glia, neurons, and vessels through calcium imaging and direct blood flow measurements. It is used to identify cellular elements that control vascular responses under…show more content…
This method utilizes the electrochemical properties of the neural membrane, where voltage-sensitive dyes change fluorescence. A sample is exposed to a monochromatic excitation light, and the fluorescent signal is recorded. The imaging depth is 1 mm and the spatial resolution is dependent on the optical system. Unfortunately, the method is invasive and toxic. Photo acoustic microscopy(PAM) combines optical and ultrasound techniques to obtain excellent optical absorption contrast and spatial resolution. Optical-PAM gives a cellular level resolution, while acoustic-resolution PAM has a high lateral resolution. The optical source is a laser wavelength and doesn’t need a contrast agent. However, this method can be used to image cerebral blood flow and oxygenation only. Near-infrared spectroscopy(NIS) consists of laser wavelengths that measure changes in activity through the measurements of HbO and HbR. Although it has lower spatial resolution, it is lower in cost, and more portable. It can be used for open brain imaging, human research, and animal experiments. Because the use of one technique provides a single aspect of the processes going on for a sample, it is better to utilize multimodal imaging techniques. However, in terms of the usage of these techniques for human studies, the thickness of the skull creates spatial resolution limitations, and therefore most can only…show more content…
But it briefly discusses a prior theory. This can be attributed as a strength, since this dispels any confusion or disagreement others in this field might have when reading this. Towards the end of the introduction, the article also gives a synopsis of the techniques to be discussed. A table comparing each technique is also given within the article, making it easier to compare. The article also speculates about the future of each technique and how it might be improved to increase their
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