Method for functional study of mitochondria in rat hypothalamus
Résumé
Different roles of mitochondria in brain function according to brain area are now clearly emerging. Unfortunately, no technique is yet described to investigate mitochondria function in specific brain area. In this article, we provide a complete description of a procedure to analyze the mitochondrial function in rat brain biopsies. Our two-step method consists in a saponin permeabilization of fresh brain tissues in combination with high-resolution respirometry to acquire the integrated respiratory rate of the biopsy. In the first part, we carefully checked the mitochondria integrity after permeabilization, defined experimental conditions to determine the respiratory control ratio (RCR), and tested the reproducibility of this technique. In the second part, we applied our method to test its sensitivity. As a result, this method was sensitive enough to reveal region specificity of mitochondrial respiration within the brain. Moreover, we detected physiopathological modulation of the mitochondrial function in the hypothalamus. Thus this new technique that takes all cell types into account, and does not discard or select any mitochondria sub-population is very suitable to analyze the integrated mitochondrial respiration of brain biopsies.
Mots clés
Animals
Brain/drug effects/physiology
Cell Respiration
Fasting/physiology
Hyperglycemia/physiopathology
Hypothalamus/drug effects/*physiology/ultrastructure
Laboratory Techniques and Procedures
Male
Microscopy
Electron
Mitochondria/*physiology/ultrastructure
Oxygen Consumption
Permeability/drug effects
Phosphorylation
Rats
Wistar
Zucker
Saponins/pharmacology
Stress
Physiological