Bioenergetic analysis of isolated cerebrocortical nerve terminals on a microgram scale: spare respiratory capacity and stochastic mitochondrial failure.

摘要: Pre-synaptic nerve terminals (synaptosomes) require ATP for neurotransmitter exocytosis and recovery ionic homeostasis, are consequently abundantly furnished with mitochondria. mitochondrial dysfunction is implicated in a variety of neurodegenerative disorders, although there no precise definition the term 'dysfunction'. In this study, we test hypothesis that partial restriction electron transport through Complexes I II synaptosomes to mimic possible defects associated Parkinson's Huntington's diseases respectively, sensitizes individual depolarization under conditions enhanced proton current utilization, even though these stresses within respiratory capacity when averaged over entire population. We combine two novel techniques, firstly using modification plate-based respiration glycolysis assay requires only microgram quantities synaptosomal protein, secondly developing an improved method fluorescent imaging statistical analysis single synaptosomes. Conditions defined optimal substrate supply situ mitochondria mouse cerebrocortical synaptosomes, energetic demands ion cycling action-potential firing at plasma membrane additionally determined.