Gliosis
Encyclopedia
Gliosis is a proliferation of astrocyte
s in damaged areas of the central nervous system
(CNS). This proliferation usually leads to the formation of a glial scar
.
Astrocytes are relatively large glial cell
s and have various functions, including accumulating in areas where neuron
s have been damaged. It is the most important histopathological sign of CNS injury. Astrocytes undergo both hypertrophy and hyperplasia. The nucleus enlarges and becomes vesicular and nucleolus becomes prominent. Previously scant cytoplasm expands and becomes bright pink or red and irregular from which arise numerous processes (gemistocytic astrocyte).
Bergmann gliosis is associated with anoxic injury and is characterized by death of Purkinje cells.
Gliosis and neuronal loss in certain brain regions are findings seen in various neurodegenerative disorders such as Alzheimer's disease
, Korsakoff's syndrome
, multiple system atrophy
, prion disease, multiple sclerosis
(after an acute attack) and AIDS dementia complex
. It can also be found in Parkinson's disease, ALS and Huntington's disease.
It has also been associated with about 10% of patients with Celiac Disease or gluten-sensitivity (Archives of Neurology. 63(10):1440-6, 2006 Oct.). Gliosis damage to the brain in Celiac and gluten-sensitivity usually causes ataxia, peripheral neuropathy and/or cognitive impairment.
Gliosis is also a documented effect of neural infection by Transmissible Spongiform Encephalopathies (TSE). TSE's are better known as prion diseases, and are similar to Scrapie
and Bovine Spongiform Encephalopathy (BSE or Mad Cow Disease). Prion
s are a specific sort of incorrectly folded protein
.
Astrocyte
Astrocytes , also known collectively as astroglia, are characteristic star-shaped glial cells in the brain and spinal cord...
s in damaged areas of the central nervous system
Central nervous system
The central nervous system is the part of the nervous system that integrates the information that it receives from, and coordinates the activity of, all parts of the bodies of bilaterian animals—that is, all multicellular animals except sponges and radially symmetric animals such as jellyfish...
(CNS). This proliferation usually leads to the formation of a glial scar
Glial scar
Glial scar formation is a reactive cellular process involving astrogliosis that occurs after injury to the Central Nervous System. As with scarring in other organs and tissues, the glial scar is the body's mechanism to protect and begin the healing process in the nervous system...
.
Astrocytes are relatively large glial cell
Glial cell
Glial cells, sometimes called neuroglia or simply glia , are non-neuronal cells that maintain homeostasis, form myelin, and provide support and protection for neurons in the brain, and for neurons in other parts of the nervous system such as in the autonomous nervous system...
s and have various functions, including accumulating in areas where neuron
Neuron
A neuron is an electrically excitable cell that processes and transmits information by electrical and chemical signaling. Chemical signaling occurs via synapses, specialized connections with other cells. Neurons connect to each other to form networks. Neurons are the core components of the nervous...
s have been damaged. It is the most important histopathological sign of CNS injury. Astrocytes undergo both hypertrophy and hyperplasia. The nucleus enlarges and becomes vesicular and nucleolus becomes prominent. Previously scant cytoplasm expands and becomes bright pink or red and irregular from which arise numerous processes (gemistocytic astrocyte).
Bergmann gliosis is associated with anoxic injury and is characterized by death of Purkinje cells.
Gliosis and neuronal loss in certain brain regions are findings seen in various neurodegenerative disorders such as Alzheimer's disease
Alzheimer's disease
Alzheimer's disease also known in medical literature as Alzheimer disease is the most common form of dementia. There is no cure for the disease, which worsens as it progresses, and eventually leads to death...
, Korsakoff's syndrome
Korsakoff's syndrome
Korsakoff's syndrome is a neurological disorder caused by the lack of thiamine in the brain. Its onset is linked to chronic alcohol abuse and/or severe malnutrition...
, multiple system atrophy
Multiple system atrophy
Multiple system atrophy is a degenerative neurological disorder. MSA is associated with the degeneration of nerve cells in specific areas of the brain. This cell degeneration causes problems with movement, balance and other autonomic functions of the body such as bladder control or blood pressure...
, prion disease, multiple sclerosis
Multiple sclerosis
Multiple sclerosis is an inflammatory disease in which the fatty myelin sheaths around the axons of the brain and spinal cord are damaged, leading to demyelination and scarring as well as a broad spectrum of signs and symptoms...
(after an acute attack) and AIDS dementia complex
AIDS dementia complex
AIDS dementia complex is a common neurological disorder associated with HIV infection and AIDS. It is a metabolic encephalopathy induced by HIV infection and fueled by immune activation of brain macrophages and microglia...
. It can also be found in Parkinson's disease, ALS and Huntington's disease.
It has also been associated with about 10% of patients with Celiac Disease or gluten-sensitivity (Archives of Neurology. 63(10):1440-6, 2006 Oct.). Gliosis damage to the brain in Celiac and gluten-sensitivity usually causes ataxia, peripheral neuropathy and/or cognitive impairment.
Gliosis is also a documented effect of neural infection by Transmissible Spongiform Encephalopathies (TSE). TSE's are better known as prion diseases, and are similar to Scrapie
Scrapie
Scrapie is a fatal, degenerative disease that affects the nervous systems of sheep and goats. It is one of several transmissible spongiform encephalopathies , which are related to bovine spongiform encephalopathy and chronic wasting disease of deer. Like other spongiform encephalopathies, scrapie...
and Bovine Spongiform Encephalopathy (BSE or Mad Cow Disease). Prion
Prion
A prion is an infectious agent composed of protein in a misfolded form. This is in contrast to all other known infectious agents which must contain nucleic acids . The word prion, coined in 1982 by Stanley B. Prusiner, is a portmanteau derived from the words protein and infection...
s are a specific sort of incorrectly folded protein
Protein folding
Protein folding is the process by which a protein structure assumes its functional shape or conformation. It is the physical process by which a polypeptide folds into its characteristic and functional three-dimensional structure from random coil....
.