ABSTRACT
The morphology of mitochondria can inform about their functional state and, thus, about cell vitality. For example, fragmentation of the mitochondrial network is associated with many diseases. Recent advances in neuronal imaging have enabled the observation of mitochondria in live brains for long periods of time, enabling the study of their dynamics in animal models of diseases. To aid these studies, we developed an automatic method, based on supervised learning, for quantifying the degree of mitochondrial fragmentation in tissue images acquired via two-photon microscopy from transgenic mice, which exclusively express Enhanced cyan fluorescent protein (ECFP) under Thy1 promoter, targeted to the mitochondrial matrix in subpopulations of neurons. We tested the method on images prior to and after cardiac arrest, and found it to be sensitive to significant changes in mitochondrial morphology because of the arrest. We conclude that the method is useful in detecting morphological abnormalities in mitochondria and, likely, in other subcellular structures as well.
Subject(s)
Automation, Laboratory/methods , Brain/pathology , Image Processing, Computer-Assisted/methods , Microscopy, Fluorescence, Multiphoton/methods , Mitochondria/pathology , Neurons/pathology , Pathology/methods , Animals , Artificial Gene Fusion , Green Fluorescent Proteins/analysis , Green Fluorescent Proteins/genetics , Heart Arrest/pathology , Mice, Transgenic , Staining and Labeling/methodsABSTRACT
The effects of repetitive mild hypobaric hypoxic preconditioning upon pro- and antioxidant systems in rat hippocampus were studied. It was found that three-trial preconditioning by mild hypobaric hypoxia (360 mm Hg, 2 h) induced moderate oxidative stress immediately after the last preconditioning trial. In addition, it down-regualted the levels of peptide antioxidants (Trx-1, Trx-2, Cu,Zn-SOD) and several lipid peroxidation products 24 h later.
Subject(s)
Adaptation, Physiological/physiology , Antioxidants/metabolism , Hippocampus/metabolism , Hypoxia/metabolism , Oxidative Stress/physiology , Animals , Cell Membrane/enzymology , Cell Membrane/metabolism , Hippocampus/enzymology , Hypoxia/enzymology , Hypoxia/physiopathology , Lipid Peroxides/metabolism , Male , Neurons/enzymology , Neurons/metabolism , Rats , Rats, Wistar , Superoxide Dismutase/biosynthesis , Thioredoxins/biosynthesisABSTRACT
There was studied effect of severe hypobaric hypoxia and subsequent reoxygenation on level and dynamics of lipid peroxidation in membranes of neocortex cells and in mitochondria-enriched neocortex fraction of non-preconditioned rats and of rats preconditioned thrice with a moderate hypobaric hypoxia. The threefold hypoxic preconditioning increasing brain resistance has been shown to significantly prevent disturbance of lipid peroxidation processes in neocortex--one of the most hypoxia-sensitive brain structures--and to modify development of these processes in mitochondria.
