Calcium Regulation by Calcium-Binding Proteins in Neurodegenerative Disorders

Claus W. Heizmann and Katharina Braun ore than 10,000 articles were published in 1994 on calcium, M 2 emphasizing the widespread interest and progress in Ca +­ 2 related research. This book focuses mainly on Ca + -binding pro­ 2 teins in the central nervous system, where Ca + ions have been found to activate fundamental processes such as release of neu­ rotransmitters, axonal flow, long term potentiation, cell motility, differentiation, secretion, and apoptosis. It has also been found that a number of neurodegenerative disorders have been attributed 2 1 to aberrations of intracellular Ca + homeostasis. 2 2 Intracellular Ca + levels and Ca + signaling within cells must 2 3 2 be tightly controlled. • Ca + overload as a result of seizures or ischemia is supposed to activate biochemical processes, leading to enzymatic breakdown of proteins and lipids, malfunctioning of 2 mitochondria, energy failure and ultimately cell death. There is 3 experimental evidence that electrically induced irreversible depo­ larization of hippocampal neurons, which may be an early indica­ 2 tion of neuronal damage, could be prevented by injecting Ca + chelators and thereby increasing intracellular buffering capacity. Thus, it is reasonable to assume that neurons containing certain 2 intracellular Ca +-binding proteins, and therefore having a greater 2 capacity to buffer Ca +, could be more resistant to degeneration.