White matter

White matter is a part of the central nervous system made up of **nerve fibers that carry signals and information** between different areas of the brain and spinal cord. White matter consists of **bundles of axons**, organized in three columns per side (anterior, posterior, and lateral), which appear white because they are covered by **myelin**. This is a whitish substance produced by oligodendrocytes that wraps around nerve fibers and acts as an **electrical insulator**, **improving the speed of nerve impulse conduction**. Myelin is composed of 40% water, lipids, and proteins.

Characteristics of White Matter

White matter contrasts with gray matter, which is mainly composed of neuron cell bodies and dendrites, associated with brain areas involved **in information processing and control**. White matter is distributed differently across brain regions, concentrating especially in the spinal cord and inner areas, playing an essential role in the **coordination of cognitive, sensory, and motor activities**.

It was originally considered static, but recent studies have shown that it can change and adapt over time, especially in adulthood. The plasticity of white matter can be influenced by learningIl termine apprendimento - con i sinonimi imparare, assimila... More, experience, and various environmental conditions.

White Matter Diseases

White matter diseases can be genetic or acquired, progressive or static, and cause neurological symptoms including muscle weakness, coordination problems, and difficulty in nerve impulse transmission.

Different pathologies are distinguished:

• demyelinating, autoimmune, infectious, vascular, or toxic-metabolic in nature, where myelin is damaged or destroyed. Common demyelinating diseases include multiple sclerosis, inflammatory optic neuropathy, and chronic inflammatory demyelinating neuropathy;
• dysmyelinating, where myelin is not produced due to synthesis or metabolic errors. Examples include adrenoleukodystrophy, Krabbe disease, and Alexander disease;
• hypomyelinating, with defective myelination and reduced or incomplete production of myelin.