Neurovascular unit

Neurovascular Unit

The Neurovascular Unit (NVU) represents a critical and complex system in the brain that encompasses a dynamic ensemble of neural cells, vascular cells, and extracellular matrix components. This unit is fundamental in maintaining the blood-brain barrier (BBB) and in regulating cerebral blood flow, thereby ensuring the proper functioning of the central nervous system (CNS).

Components

The NVU is composed of several key components:

• Endothelial Cells: These cells line the interior surface of blood vessels and are integral in forming the BBB, controlling the passage of substances between the blood and the brain.
• Astrocytes: Star-shaped glial cells that provide support to the BBB and are involved in neurotransmitter regulation and blood flow.
• Pericytes: Embedded in the basement membrane of capillaries, these cells regulate blood flow, vascular stability, and permeability.
• Microglia: The resident immune cells of the CNS, involved in immune surveillance and response to injury.
• Neurons: The primary signaling cells of the CNS, which communicate through electrical and chemical signals.
• Extracellular Matrix (ECM): A complex network of proteins and other molecules that provide structural and biochemical support to surrounding cells.

Function

The NVU plays a pivotal role in the homeostasis of the CNS environment. Its functions include:

• Regulation of the BBB, which protects the brain from harmful substances in the blood while allowing the passage of essential nutrients.
• Modulation of cerebral blood flow in response to neuronal activity, ensuring that active regions of the brain receive more blood supply.
• Maintenance of the ionic balance within the CNS, crucial for proper neuronal function.
• Response to injury and involvement in the CNS's innate immune response.

Pathology

Dysfunction of the NVU is associated with various neurological disorders, including:

• Stroke
• Alzheimer's Disease
• Multiple Sclerosis
• Traumatic Brain Injury
• Glioblastoma

Understanding the mechanisms underlying NVU dysfunction in these conditions is crucial for developing targeted therapeutic strategies.

Research and Therapeutic Implications

Research on the NVU is focused on understanding its complex interactions and the role it plays in CNS health and disease. Therapeutic strategies targeting the NVU are being explored for several neurological conditions, with the aim of restoring or preserving NVU function to protect against disease progression and improve outcomes.

See Also

• Blood-brain barrier
• Cerebral blood flow
• Central nervous system
• Neuroinflammation