POSTER PRESENTATION Open Access

Differential contribution of A-type potassiumcurrents in shaping neuronal responses tosynaptic inputAdrian Smith1,2,3*, Maytee Cruz-Aponte1,3, Erin C McKiernan2, Sharon Crook1,2,3, Marco Herrera-Valdez1,2,4

From Twentieth Annual Computational Neuroscience Meeting: CNS*2011Stockholm, Sweden. 23-28 July 2011

Neurons receive input from thousands of excitatory andinhibitory synapses, but they are not merely passivereceivers and transmitters of information. The intrinsicproperties of neurons, and more specifically the collec-tion of ion channels expressed, influence a cell’s excit-ability and integration processes. The role of differentvoltage-dependent transient (A-type) and persistent(delayed rectifier) potassium currents in shaping theactivity of neurons in response to synaptic input is notwell understood. We developed a biophysical modelincorporating realistic synaptic input [1] to investigatethe specific roles played by distinct A-type potassiumchannels encoded by different genes, namely Shaker/Kv1and Shal/Kv4. We find that these two channel types,which are functionally distinguished by their inactivationproperties, exert different control mechanisms on thetransitions between rest and repetitive spiking in neu-rons. Bifurcation analysis is used to characterize theinfluence of each channel and the overall behavior ofthe membrane as a function of the relative presence ofthe two A-type channels. We found that the influenceof each channel type depends on the resting potential ofthe neuron, suggesting that modulation and/or networkstates may shift their relative contribution. For example,at a particular membrane potential, Shal/Kv4 channelsare more likely to mediate delays to first spike inresponse to excitatory input. Overall, this work increasesour understanding of the interaction between intrinsicproperties and synaptic input in creating neuronalresponse profiles. Further, we provide a link between

relative gene expression and bifurcation structures indynamical systems modeling neuronal membranes.

Author details1Mathematical, Computational and Modeling Sciences Center, Arizona StateUniversity, Tempe, AZ, 85287, USA. 2School of Life Sciences, Arizona StateUniversity, Tempe, AZ, 85287, USA. 3School of Mathematical and StatisticalSciences, Arizona State University, Tempe, AZ, 85287, USA. 4School of HumanEvolution and Social Change, Arizona State University, Tempe, AZ, 85287,USA.

Published: 18 July 2011

Reference1. Destexhe A, Maien ZF, Sejnowski TJ: An efficient method for computing

synaptic conductances based on a kinetic model of receptor binding.Neural Computation 1994, 1:14-18.

doi:10.1186/1471-2202-12-S1-P147Cite this article as: Smith et al.: Differential contribution of A-typepotassium currents in shaping neuronal responses to synaptic input.BMC Neuroscience 2011 12(Suppl 1):P147.

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* Correspondence: ansmit17@asu.edu1Mathematical, Computational and Modeling Sciences Center, Arizona StateUniversity, Tempe, AZ, 85287, USAFull list of author information is available at the end of the article

Smith et al. BMC Neuroscience 2011, 12(Suppl 1):P147http://www.biomedcentral.com/1471-2202/12/S1/P147

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