How is CNS aging?

During normal aging the weight of the brain decreases slightly The meninges thicken and are fibrous The cortex atrophies and the ventricles are dilated. The number of neurons in the cortex and the hippocampus decreases Senile plaques can be seen in the hippocampus as well as neurofibrillary degeneration. Changes in enzymes and neurotransmitters can have a physiological impact on functional networks Alzheimer's disease is not linked to aging, but its frequency increases with age