A grid-based stochastic simulation of unitary and membrane Ca/sup 2+/ currents in spherical cells

We present a stochastic simulation of L-type Ca/sup 2+/ current assuming thousands of calcium channels on the membrane of a spherical cell. We propose a three-state Markov model to simulate the individual contribution of each channel. Rather than using a statistical approximation, we actually consider each individual channel transitions between states and evaluate the unitary channel current. We compare this aggregated unitary contributions with simulated whole cell currents, both in response to a depolarising voltage pulse. On the computational side, we have employed a parameter-sweep, component based approach. Being embarrassingly parallel by design, we have parallelised it in a naive manner. We argue its possible extension using algorithmic skeletons. The results presented account for hours of processing time on a dedicated grid.

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