MITOCHONDRIAL DYSFUNCTION AND BRAIN DISORDERS

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