Calcium oscillations in blood platelets and their possible role in ‘interpreting’ extracellular information by cells

Abstract

Intracellular Ca2+ ions play an important role in the transmission and treatment of information that cells obtain from the ambient environment. Having received an external signal, a cell may increase the intracellular Ca2+ concentration within fractions of a second by a factor of several hundred. This phenomenon triggers activation of various cellular systems that generate a response to the external stimulus. In many cells under the effect of external signal the concentration of Ca2+ not only increases, but also starts oscillating. Both the frequency and amplitude of the oscillations are affected by the external signal strength. There are reasons to hypothesize that the conversion of the external signal into the oscillating intracellular signal has some important informational meaning. Methods to measure the dynamics of the intracellular Ca2+ concentration and mechanisms that generate the oscillations are reviewed, and hypotheses on how the cell decodes Ca2+ concentration oscillations are presented. Consideration is focused on the platelet, the cell that plays a key role in arresting hemorrhages. If a vessel is damaged, the platelet is rapidly activated. Identical platelets are divided in the process of arresting a hemorrhage into three populations with quite different missions. The platelet seems to somehow ‘interpret’ the set of external signals and uses the Ca2+ concentration oscillations to ‘choose’ the population to which it will belong. Owing to the platelet’s relative simplicity, one can expect that studies of that cell will shortly enable the decryption of the ‘code’ that drives Ca2+ concentration oscillations.

Basic concepts and physical-chemical phenomena, that have conceptual meaning for the formation of systemic clinical thinking and formalization of the knowledge of systemic structural-functional organization of the human’s organism

“…В свою очередь, определённая характеристика такого сигнала запускает строго соответствующую последовательность биохимических событий [177,206]. Таким образом, специфический частотно-амплитудный паттерн осцилляций концентрации ионов Ca 2+ обеспечивает клетку эффективным средством для адекватных её реакций на различные внешние сигналы [207,208].…”

Stochastic dynamics in the Li–Rinzel calcium oscillation model

“…Inevitably present random perturbations, even of low intensity, can significantly change the behavior in systems with strong nonlinearity. [9][10][11][12][13][14][15][16] Stochastic effects play an important role in calcium oscillations and analysis of results of random forcing is a subject of many investigations (see, e.g., previous works 5,[17][18][19][20][21] ).…”