Investigations of calcium homeostasis mechanisms in nerve cells and their alterations during brain pathology.

The paper summarises new data about the molecular mechanisms of calcium homeostasis maintenance in nerve cells and generation of intracellular calcium transients--the most general secondary messenger triggering or modulating all steps of neuronal life cycle and its main functions. It describes the low- and high-voltage activated plasmalemmal ion channels injecting Ca2+ into the cell, cytosolic buffering systems which rapidly bind the main part of injected ions, properties of intracellular stores accumulating Ca2+ ions due to the activity of CERCA-pumps and releasing them back into the cytosol via the CICR mechanism, possible participation of mitochondria in this process, extrusion of Ca2+ from the cell by PMCA-pumps. By introducing new techniques, quantitative characteristics are obtained of these mechanisms and of their participation in determining the amplitude and kinetics of calcium signals in different neurons, as well as their changes during ageing and some forms of brain pathology.