Membrane potential changes in activated cells: connection with cytosolic calcium oscillator

Area of Science:

• Biophysics
• Cellular Electrophysiology
• Theoretical Biology

Background:

• Cellular activation by external stimuli like hormones and neurotransmitters often results in dynamic changes in cell membrane potential.
• The role of intracellular calcium oscillations in cellular signaling is well-established, but their direct impact on membrane potential dynamics requires further elucidation.

Purpose of the Study:

• To develop a theoretical model explaining how cytosolic calcium oscillations can independently induce periodic variations in cell membrane potential.
• To investigate the primary contribution of potassium (K+) diffusion potential to membrane potential dynamics during calcium oscillations.

Main Methods:

• Development of a theoretical model based on nonlinear dynamical systems.
• Utilizing a one-pool model to represent calcium ion (Ca2+) release from intracellular stores.
• Numerical calculations to analyze the model's behavior.

Main Results:

• The model demonstrates that oscillations in intracellular calcium concentration are sufficient to induce oscillations in cell membrane potential.
• It is shown that these effects can occur without additional interaction mechanisms involving ionic channels in the plasma membrane.
• The model highlights the significance of K+ diffusion potential in mediating these electrophysiological changes.

Conclusions:

• Intracellular calcium oscillations are a key intrinsic mechanism driving cell membrane potential dynamics.
• The developed theoretical framework provides insights into the electrophysiological consequences of calcium signaling.
• This model offers a simplified yet powerful approach to understanding cell membrane potential regulation in response to biological signals.