What Is Gray Matter?
Gray matter is a vital tissue of the brain and the spinal cord. It plays a key role in carrying out normal day-to-day activities. It comprises a high concentration of gray matter. A high concentration of neuronal (nuclei) bodies, axon endings, and dendrites are present in the gray matter.
A neuronal cell chiefly comprises of:
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A large nerve cell body containing a nucleus. The nerve cell nucleus is mainly responsible for controlling the cellular activities and carries the genetic information.
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An elongated axon that is responsible for transmitting electric sensations.
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Dendritic branches for receiving neuronal electrical signals from other cells of the body.
The gray matter is usually developed at an early stage of fetus formation. After the birth of a baby, the gray matter volume increases up to eight years of age. After that, its density increases until 21 years, which leads to high processing and intellectual development. One thing to note is that the neurons do not regenerate. Once they die, the damage is permanent.
The gray matter is made up of several grooves called sulci and bumps called gyri. This sheet of gyri and sulci consists of several neurons. These gyri and sulci allow extensive expansion of the brain during development. Therefore, the human brain has multiple folds and more gray matter than the animals.
What Is the Function of Gray Matter?
The main function of the gray matter is to process the information through the nerve cells and release it in the form of signals through axons that are found in the white matter. Hence, it helps in controlling movement and processing memory and emotions. In short, gray matter is responsible for human functioning.
How to Differentiate Between Gray Matter and White Matter?
The human brain consists of 40 percent gray matter and 60 percent white matter. They are both important parts of the central nervous system. The major difference is their composition. The gray matter primarily comprises neuronal cell bodies and dendritic branches. On the other hand, the white matter consists of neuronal axons that are responsible for transmitting electrical impulses to other parts of the central nervous system (brain and spinal cord).
The presence or lack of myelin sheath (a membrane covering the neuronal axons) marks another anatomical difference between gray and white matter. Gray matter consists of unmyelinated nerve cells, whereas white matter consists of myelinated nerve cells.
What Is the Pathogenesis of Gray Matter Brain Damage?
The gray matter brain damage occurs as the nerve cells start to die. Gray matter atrophy begins with neuronal death. One of the most common causes of nerve cell death in the gray matter is ischemia (lack of blood supply to the nerve cells). As the nerve cells present in the gray matter are continuously working and processing important brain messages, they require a lot of energy (oxygen through the blood flow). The nerve cell bodies (nuclei) are responsible for keeping the cell alive. Therefore, during a hypoxic (when the oxygen level is low) event such as ischemia, the gray matter suffers injury, eventually leading to gray matter brain damage.
Another important cause of gray matter brain damage is when there is a change in the local environment, such as when physical damage occurs or during a brain stroke (hematoma). Sometimes, there is an increase in the release of certain toxic factors by the damaged neurons and glial cells that may increase the gray matter brain injury effect. Such events lead to the initiation of apoptosis (programmed cell death).
Once the gray matter is damaged, the cell is unable to support its axon endings or dendritic branches. This leads to the death of the entire nerve cell. Neurons with large cell bodies and long axons experience more damage, which is usually irreversible. Whereas after a white matter damage, a healthy neuronal cell body has the ability to repair a damaged axon.
The form and extent of the gray matter injury decide the recovery rate.
What Are the Conditions Associated with Gray Matter Brain Damage?
Some conditions related to gray matter brain damage include:
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Alzheimer’s Disease: There is an abnormal protein build-up in the brain that causes Alzheimer’s disease. The build-up of proteins like amyloid protein and tau protein causes the nerve cells in the gray matter to suffer damage.
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Parkinson’s Disease: This disease occurs due to a loss of neuronal cells in the gray matter in a part of the brain called the substantia nigra.
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Multiple Sclerosis: Multiple sclerosis is considered a white matter disease, chiefly a demyelinating pathology. However, recent studies show that multiple sclerosis results in the loss of deep gray matter.
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Brain Trauma: If there is a traumatic brain injury, the gray matter may suffer damage due to an intracerebral hemorrhage (brain hematoma), which can cause gray matter brain cell death.
What Are the Signs and Symptoms of Gray Matter Brain Damage?
The clinical signs and symptoms of gray matter brain damage include-
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Loss of brain memory.
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Cognitive impairment, like issues with language, reasoning, and judgment.
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Motor issues such as fine motor skills.
How Is Gray Matter Brain Damage Diagnosed and Treated?
The doctors usually suggest MRI (magnetic resonance imaging) to assess brain health. It helps to diagnose conditions like Alzheimer’s disease and dementia. There is no known treatment for gray matter brain damage. Once the nerve cells die, they lose their ability to regenerate. The only possible way is to manage the clinical symptoms. The prognosis is better in the case of young children than adults.
Conclusion
Gray matter brain damage is a serious medical condition that has no proper cure to date. It is very important to take care of the gray matter to prevent gray matter damage. Proper blood and oxygen supply is essential for brain health. One should do regular exercise, keep weight under control, and maintain blood pressure. Stress management is very important for brain health.
