Dynamic Clamp
Amanda Preyer, Georgia Institute of Technology, Atlanta, Georgia, USA
Sharon Norman, Georgia Institute of Technology, Atlanta, Georgia, USA
Robert J Butera, Georgia Institute of Technology, Atlanta, Georgia, USA
Published online: September 2013
DOI: 10.1002/9780470015902.a0020293.pub2
Abstract
The dynamic clamp technique uses the membrane voltage measured from an electrically excitable cell to solve computational
ion channel models running in real time. These models comprise differential equations and ionic current calculations driven
in part by the measured voltage. The current calculated from these simulations is then injected into the cell in a feedback
configuration to create ionic currents that can simulate intrinsic ionic currents within single cells, as well as synaptic
currents among cells to create small networks of cells. Applications include functional assessment of insertion or deletion
of ion channels on membrane electrodynamics and studying interactions among coupled cells. Specific examples include studies
of action potential propagation between cardiac myocytes and studying mechanisms of synchrony between coupled neurons.
Key Concepts:
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The dynamic clamp is an electrophysiological technique that integrates the real‐time simulation of ion channel kinetics with
electrophysiological experiments.
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Simulated ion channels are driven by recorded membrane potentials and the calculated current is injected into a cell, altering
the cell's membrane electrodynamics.
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Applications include studies of ion channel mechanisms and dynamics of coupling of activity among cells.
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The implementation of real‐time simulations required dedicated special purpose hardware and/or software suitable for closed‐loop
tasks with low latencies (time delays).
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Recently developed low‐cost embedded systems may emerge as the platform of choice for implementing this technique.
Keywords: electrophysiology; real‐time simulation; embedded system; cardiac; myocyte; neuron; real-time
References
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Further Reading
Butera R and McCarthy M (2004) Analysis of real‐time numerical integration methods applied to dynamic clamp experiments. Journal of Neural Engineering 1: 187–194.
Butera RJ, Wilson CG, DelNegro CA and Smith JC (2001) A methodology for achieving high‐speed rates for artificial conductance injection in electrically excitable biological cells. IEEE Transactions on Biomedical Engineering 48: 1460–1470.
Dorval AD, Christini DJ and White JA (2001) Real‐time Linux dynamic clamp: a fast and flexible way to construct virtual ion channels in living cells. Annals of Biomedical Engineering 29: 897–907.
Goaillard JM and Marder E (2006) Dynamic clamp analyses of cardiac, endocrine, and neural function. Physiology 21: 197–207.
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Pinto RD, Elson RC, Szucs A et al. (2001) Extended dynamic clamp: controlling up to four neurons using a single desktop computer and interface. Journal of Neuroscience Methods 108(1): 39–48.
Preyer AJ and Butera RJ (2005) Neuronal oscillators in Aplysia californica that demonstrate weak coupling in vitro. Physical Review Letters 95: 138103.
Prinz AA, Abbott LF and Marder E (2004) The dynamic clamp comes of age. Trends in Neurosciences 27: 218–224.
Raikov I, Preyer A and Butera RJ (2004) MRCI: a flexible real‐time dynamic clamp system for electrophysiology experiments. Journal of Neuroscience Methods 132: 109–123.