Influence of Internal Noise on Rhythmic Calcium Bursting

Abstract

The chemical Langevin method is adopted to study effects of intrinsic noise in calcium bursting oscillations. Results show that by changing the cell volume and thus tuning the strength of internal noise the calcium oscillations show different performance. With the addition of small magnitude intrinsic noise the bursting oscillations do not appear irregular, for moderate volumes relative regular bursting oscillations are observed and internal noise shortens the period of bursting oscillations. As the volume decreases, the level of internal noise increases. Thus, for the volume small enough, the level of internal noise becomes so high that bursting behavior is disrupted, resulting in random oscillations. The most interesting phenomenon is that with the decrease of cell volume the bursting oscillations disappear entirely and only spikes remain. This will be helpful for understanding frequency encoding.