Mitochondrial dysfunction and brain disorders

Summary ing to the mitochondrial theory of aging, it is expected that in postmitotic tissues, such as nervous system, an accumulation of damage to mitochondrial DNA could lead to a progressive failure of mitochondrial function during senescence. NADH-Coenzyme Q reductase (Complex I) activity should be severely affected since 7 subunits of this enzymatic complex are encoded by mitochondrial DNA. We decided to investigate the modifications occurring to this particular complex during aging in two different neuronal populations from aged rats, using rotenone sensitivity as a functional parameter of the subunits encoded by mitochondrial DNA. In order to have an easy model to study mitochondrial modifications during senescence and in other neurodegenerative disorders, we also investigated mitochondrial membranes from platelets of young and old individuals. In all systems investigated, a decease of rotenone sensitivity in aging was observed.