Brain mitochondria and brain diseases

It is looking more and more often than the cerebral energy has an important role in the origin of many disorders and diseases such as Alzheimer's and other dementias, stroke, Parkinson's, multiple sclerosis and aging.
In particular, it points toward the oxidative damage caused by free radicals (ROS) and the decline of mitochondrial function, with subsequent energetic failure causing, as two factors that make a key contribution in this process of degeneration of neurons .

Mitochondria
Mitochondria are cellular organelles responsible for obtaining the energy necessary for proper cell function. They pyruvate and fatty acids derived from dietary substances pass through the Krebs cycle and subsequently by a process called mitochondrial oxidative phosphorylation for ATP, the body's main energy molecules.
Mitochondria, using molecular oxygen (O2), produce a large amount of energy (up to 15 times more than cells that do not use O2). However, this increase in energy efficiency has a downside. The O2 molecule has a great hunger for electrons and throughout the process mitochondrial oxygen free radicals general (ROS) that cause damage in various cellular structures and functions, beginning with the mitochondria.

Oxygen free radicals (ROS)
Human metabolism produces ROS intrinsically. Even when the mitochondria works best under the most favorable conditions, 5% oxygen using ROS becomes. This does not take into account the presence of other internal or external factors that can increase these levels. To counter some of the effect of these ROS, organisms have antioxidant defense systems. Even so, these systems are not 100% efficient cells gradually accumulate damage, especially the mitochondria themselves. This cumulative damage causes a progressive loss of efficiency of physiological processes, including a decreased ability to repair the damage.
In particular, damage to mitochondria that makes it more difficult to manage the freed electrons with a loss of functional integrity on the one hand reduces the energy production capacity (by decreasing regeneration capacity) and other increases leakage of electrons (which in turn increases oxidative damage). So, we enter a vicious circle.

Special characteristics of brain
The human brain has special characteristics that make it especially sensitive to ROS and oxidative degeneration.

*Automatic Translation