Vascular Dysfunction and Neurodegenerative Disease

The brain is the most metabolically active and complex organ in the human body, consisting of nearly 100 billion neurons and with over 100 trillion intricate connections. In order to maintain its intensive metabolic demands, the brain is highly vascularized, with nearly every neuron possessing its own capillary and total capillary length of nearly 400 miles. The integrity of the cerebral vascular system is accomplished through a vast vascular network of arteries, arterioles, capillaries, and veins which assure the continuous supply of oxygen and nutrients as well as provide a pathway for washing out metabolic waste products. Structural and functional integrity of blood vessels for adequate blood supply delivery is essential to maintain normal neurological function. A healthy neuronal-vascular relationship is critical for proper neurological processing, and vascular insults can consequentially initiate a cascade of molecular events which ultimately may result in neurodegeneration. Deterioration of brain functionality occurs progressively with advancing age, and an aged brain is consequently highly prone to neurodegenerative disorders. With increasing awareness of the importance of the neurovascular contribution to neurodegenerative disease, a better understanding of the contributory pathophysiological mechanisms is necessary. This chapter will cover the link between neurovascular dysfunction and neurodegeneration.