Neurodegenerative disorders and aging. Alzheimer's disease and Parkinson's disease--common ground

Microglia in the normally aged hippocampus

The hippocampus plays important roles in the regulation and combination of short and long term memory and spatial navigation with other brain centers. Aging is accompanied by a functional decline of the hippocampus and degenerative disease. Microglia are major immune cells in the central nervous system and response to degenerative changes in the aged brain. In this respect, functional and morphological changes of the hippocampus have been closely related to microglial changes during normal aging with or without disease. Therefore, in this review, we discuss morphological and functional changes of the hippocampus and microglia in the aging brain.

Disulfide-linked S100 beta dimers and signal transduction

S100 beta is a calcium-binding protein with neurotrophic and mitogenic activities, both of which may be mediated by the protein's ability to stimulate an increase in intracellular free calcium ([Ca2+]i). These extracellular trophic activities of S100 beta require a disulfide-linked, dimeric form of the protein. In this chapter, we present a minireview on the current state of knowledge concerning extracellular functions of S100 beta, with emphasis on the potential relevance of these activities to neuropathological disorders. We also report a simplified procedure for preparation of pharmacological amounts of biologically active S100 beta dimers, based on the finding that formation of disulfide-linked S100 beta dimers can be stimulated by the presence of calcium or lipid.

Binswanger's disease (Part II): Pathogenesis of subcortical arteriosclerotic encephalopathy and its relation to other dementing processes

Subcortical arteriosclerotic encephalopathy (SAE) is a common though infrequently recognized dementia of the elderly. The unique vascular anatomy of the subcortical white matter and central brain stem probably predisposes those regions to chronic ischemia and incomplete infarction in the presence of various cardiovascular and hemodynamic insults. Recent studies have begun to define the risk factors for SAE, and others have shown it to be a condition frequently comorbid with the dementias of Alzheimer's disease, the multi-infarct state, and normal pressure hydrocephalus. Recent research into the etiologies of these disorders suggest certain pathogenetic links between them, strongly implying that they are not neatly distinct disease entities, as is commonly believed, and accounting for some of the overlap between these dementing illnesses seen clinically.