Campus Event Calendar
Event Entry
What and Who
How to quantify information transfer in signaling systems
Dr. Jürgen Pahlke
University of Manchester
ZBI Kolloquium
AG 1, AG 3, AG 4, AG 5, SWS, RG1, MMCI
Public Audience
English
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Date, Time and Location
Wednesday, 28 October 2009
17:00
60 Minutes
E1 4
024
Saarbrücken
Abstract
Calcium ions act as second messenger in many cell types. They transfer
extracellular signals (e.g. from hormones) to targets within the cell,
such as Ca2+-dependent enzymes or transcription factors. Since a
number of different effectors and cellular targets exist, it has been
suggested, that specific information is encoded in the amplitude,
frequency and waveform of the Ca-signal and decoded again, later on,
by cellular targets. After stimulation, the calcium concentration in
the cytosol of hepatocytes, for example, can display complex dynamic
behavior including spiking and bursting oscillations.
Using the information-theoretic measure Transfer Entropy we studied
the properties of this signal transduction under different conditions.
To this end, we coupled a simple Ca2+-dependent enzyme activation
process to a model of calcium oscillations. We simulated the system
stochastically to account for random fluctuations in the case of low
particle numbers. To approximate the rate of information transfer we
analyzed the resulting time series for different levels of activation
and different numbers of particles using kernel density estimation.
extracellular signals (e.g. from hormones) to targets within the cell,
such as Ca2+-dependent enzymes or transcription factors. Since a
number of different effectors and cellular targets exist, it has been
suggested, that specific information is encoded in the amplitude,
frequency and waveform of the Ca-signal and decoded again, later on,
by cellular targets. After stimulation, the calcium concentration in
the cytosol of hepatocytes, for example, can display complex dynamic
behavior including spiking and bursting oscillations.
Using the information-theoretic measure Transfer Entropy we studied
the properties of this signal transduction under different conditions.
To this end, we coupled a simple Ca2+-dependent enzyme activation
process to a model of calcium oscillations. We simulated the system
stochastically to account for random fluctuations in the case of low
particle numbers. To approximate the rate of information transfer we
analyzed the resulting time series for different levels of activation
and different numbers of particles using kernel density estimation.
Contact
Pia Scherer-Geiss, Zentrum für Bioinformatik
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Ruth Schneppen-Christmann, 10/15/2009 12:21 -- Created document.