Neurovascular unit

An overview of the neurovascular unit and its components

Diagram of the neurovascular unit

The neurovascular unit is a complex structure that plays a critical role in maintaining the homeostasis of the central nervous system (CNS). It is composed of various cell types that work together to regulate blood-brain barrier (BBB) function, cerebral blood flow, and neuroinflammation.

Components of the Neurovascular Unit

The neurovascular unit consists of several key components:

Endothelial Cells

Endothelial cells form the inner lining of blood vessels and are crucial for the integrity of the blood-brain barrier. They regulate the passage of substances between the bloodstream and the brain and are involved in angiogenesis.

Pericytes

Pericytes are contractile cells that wrap around the endothelial cells of capillaries and venules. They play a role in the regulation of blood flow, the stability and permeability of the blood-brain barrier, and the response to injury.

Astrocytes

Astrocytes are a type of glial cell that provide structural and metabolic support to neurons. They are involved in the maintenance of the blood-brain barrier and the regulation of ion and neurotransmitter concentrations in the extracellular space.

Neurons

Neurons are the primary signaling cells of the nervous system. They interact with other components of the neurovascular unit to modulate cerebral blood flow in response to neuronal activity, a process known as neurovascular coupling.

Microglia

Microglia are the resident immune cells of the CNS. They play a role in immune surveillance, phagocytosis, and the modulation of neuroinflammation within the neurovascular unit.

Functions of the Neurovascular Unit

The neurovascular unit is essential for several critical functions:

Blood-Brain Barrier Maintenance

The neurovascular unit maintains the integrity of the blood-brain barrier, which protects the brain from potentially harmful substances in the blood while allowing the passage of essential nutrients.

Regulation of Cerebral Blood Flow

Through neurovascular coupling, the neurovascular unit ensures that cerebral blood flow is matched to the metabolic demands of neuronal activity, thus maintaining optimal brain function.

Response to Injury and Disease

In response to brain injury or neurological disease, the neurovascular unit can undergo changes that affect its function. This can lead to edema, inflammation, and disruption of the blood-brain barrier.

Clinical Significance

Dysfunction of the neurovascular unit is implicated in various neurological disorders, including stroke, Alzheimer's disease, and multiple sclerosis. Understanding the interactions within the neurovascular unit is crucial for developing therapeutic strategies for these conditions.

Related pages

• Blood-brain barrier
• Cerebral blood flow
• Neuroinflammation
• Glial cells