In some of these diseases, such as Alzheimer disease and Parkinson disease , there are also specific histopathologic changes. In others, there is only neuronal loss, brain atrophy and gliosis. A clinical example of plasticity is resumption of a function, e.g. speaking or control of swallowing, by another group of neurons when the neurons that originally performed this function are lost due to a stroke. The best known laboratory example of plasticity is long term potentiation. The neuronal structure, especially the density of dendritic spines, changes as a result of neuronal activity.
Neuronal plasticity is the basis of learning.
Antibodies against this protein are routinely used to demonstrate reactive and neoplastic astrocytes. Historically, GFAP was the first immunostain to be used. Astrocytic foot processes surround brain capillaries and, during development, induce endothelial cells to form tight junctions. Endothelial tight junctions are found only in brain capillaries. Loss of the integrity of the endothelial barrier causes fluid to leak into the interstitial space, leading to vasogenic cerebral edema .