Biomedical Frontiers: SPRING/SUMMER 1997, Vol.4, No.3
Special Section: Alzheimer's Research
Glial Cell Pathology and CNS Degenerative Diseases

A Gallyas silver stain of a section of the basal ganglia from a patient with progressive supranuclear palsy showing tufted astrocytes with an abnormal accumulation of silver-positive tangle material in the cell cytoplasm. The surrounding cells are unaffected neurons.

In recent years, research interest in astrocytes and oligodendrocytes, the glial cells of the central nervous system, has increased markedly. Several studies have described extensive glial cell pathology in CNS degenerative diseases. This work is of special interest to researchers of Alzheimer's disease and other neurodegenerative disorders because some of the pathology involves tau protein. As yet, however, scientists have not determined whether the glial cell disorders are part of the process of neurodegenerative disorders or are purely a secondary effect of the diseases.

"abnormalities in glial cells are not purely secondary to neuronal degeneration"

"My point of view is that these abnormalities in glial cells are not purely secondary to neuronal degeneration," says Dr. James Goldman, professor of pathology and director of the division of neuropathology. "There are specific glial pathologies in neurological diseases that are similar to what you see in neurons in some of those same diseases. Furthermore, these glial changes differ from those produced by stroke, demyelinating diseases, trauma, or infection."

Along with Dr. Steven Chin, assistant professor of pathology, Dr. Goldman researches the changes that occur in glial cells during such neurodegenerative disorders as Alzheimer's disease, progressive supranuclear palsy, cortico-basal ganglionic degeneration, and multi-system atrophy. These changes surprised researchers when they were first discovered because until then, studies had focused on neurons, not glia. But, says Dr. Goldman, glia are easier to grow in culture; it is even possible to grow glial cells from brain specimens of patients with neurodegenerative disorders, bringing up many experimental possibilities. If glial changes are in fact due to a primary deficit in the disorder, studying living glial cells may give insights into the metabolism and pathology of the disorder that can't be gained from simply studying a slice of the brain. For example, researchers could use human glial cells to study abnormal metabolic processing of tau.