Simultaneous detection of hemodynamics, mitochondrial metabolism and light scattering changes during cortical spreading depression in rats based on multi-spectral optical imaging

• Published in: NeuroImage (Orlando, Fla.) Vol. 76; pp. 70 - 80
• Main Authors: Yin, Cui, Zhou, Fangyuan, Wang, Yaru, Luo, Weihua, Luo, Qingming, Li, Pengcheng
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 01.08.2013; Elsevier; Elsevier Limited
• Subjects: Adenine; Alzheimer's disease; Animals; Biological and medical sciences; Brain research; Cerebral Cortex - physiology; Cortical spreading depression; Cortical Spreading Depression - physiology; Cytochrome; Cytochrome aa3; Cytochrome c; Fundamental and applied biological sciences. Psychology; Hemodynamics - physiology; Hemoglobin; Laboratory animals; Light; Light scattering; Male; Metabolism; Mitochondria - metabolism; Mitochondrial DNA; Multi-spectral optical intrinsic signal imaging; Optical Imaging - methods; Rats; Rats, Wistar; Rodents; Science; Studies; Vertebrates: nervous system and sense organs; Cytochrome c; Hemoglobin; Cytochrome aa3; Multi-spectral optical intrinsic signal imaging; Light scattering; Cortical spreading depression; Rat; Enzyme; Rodentia; Cytochrome-c oxidase; Metabolism; Vertebrata; Mitochondria; Mammalia; Animal; Imaging; Oxidoreductases; Hemodynamics; Spreading depression
• ISSN: 1053-8119; 1095-9572
• DOI: 10.1016/j.neuroimage.2013.02.079

Cortical spreading depression (CSD) is a self-propagating wave of cellular depolarization that plays an important role in the development of cerebral pathology following ischemia or trauma. Optical intrinsic signal (OIS) imaging has been widely used to investigate CSD. Sources of OIS are complex and related to the changes in brain tissue absorption and scattering. The absorbing chromophores may include oxy-hemoglobin, deoxy-hemoglobin, cytochromes, flavin adenine dinucleotide (FAD) and nicotinamide adenine dinucleotide (NADH). Considering only one or part of these elements in studies involving OIS may cause inaccurate results. Thus, we simultaneously calculated changes in HbO, HbR, FAD, cytochrome c, cytochrome aa3 and light scattering during CSD by applying multi-spectral OIS imaging at 450, 470, 500, 530, 550, 570, 600, 630, and 650nm in the rat brain. We also showed that the hemodynamic changes during CSD may not be correctly estimated if the scattering and other chromophores such as FAD, cytochrome c and cytochrome aa3, are not included in the fitting model of multi-wavelength data analysis. As shown in our results, if considering the changes in scattering and other chromophores in data fitting model, deoxy-hemoglobin (HbR) showed a triphasic change while only a monophasic decrease in HbR will be resolved without considering changes in scattering and other chromophores as reported in previous studies. Moreover, our results showed that changes in cytochrome c was tightly related to OIS at 550nm, cytochrome aa3 was closely related to OIS at 450, 600 and 650nm, and FAD was closely related to OIS at 450 and 470nm during CSD. It indicates that if the contribution by these related chromophores is not considered, using OIS at these wavelengths to determine the hemoglobin changes during CSD may lead to inaccurate results. •Changes in hemodynamics, mitochondrial metabolism and light scattering•Deoxy-hemoglobin revealed triphasic changes during CSD.•Non-hemoglobin chromophores were closely related to OIS at specific wavelengths.