Coding efficiency and information rates in transmembrane signaling

Biosystems. 2000 Feb;55(1-3):15-22. doi: 10.1016/s0303-2647(99)00078-7.


A variety of cell types responds to hormonal stimuli by repetitive spikes in the intracellular concentration of calcium ([Ca(2+)](i)) which have been demonstrated to encode information in their frequency, amplitude, and duration. These [Ca(2+)](i)-spike trains are able to specifically regulate distinct cellular functions. Using a mathematical model for receptor-controlled [Ca(2+)](i) oscillations in hepatocytes we investigate the encoding of fluctuating hormonal signals in [Ca(2+)](i)-spike trains. The transmembrane information transfer is quantified by using an information-theoretic reverse-engineering approach which allows to reconstruct the dynamic hormonal stimulus from the [Ca(2+)](i)-spike trains. This approach allows to estimate the accuracy of coding as well as the rate of transmembrane information transfer. We found that up to 87% of the dynamic stimulus information can be encoded in the [Ca(2+)](i)-spike train at a maximum information transfer rate of 1.1 bit per [Ca(2+)](i)-spike. These numerical results for humoral information transfer are in the same order as in a number of sensory neuronal systems despite several orders of magnitude different time scales of operation suggesting a universal principle of information processing in both biological systems.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Action Potentials
  • Calcium / metabolism
  • Calcium Channels / metabolism
  • Cell Membrane / metabolism
  • Inositol 1,4,5-Trisphosphate Receptors
  • Receptors, Cytoplasmic and Nuclear / metabolism
  • Signal Transduction / physiology*


  • Calcium Channels
  • Inositol 1,4,5-Trisphosphate Receptors
  • Receptors, Cytoplasmic and Nuclear
  • Calcium