Subthreshold inact. of K channels modulates APs in bitufted interneurons (Korngreen et al 2005)

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Accession:83523
... In this study we show that in bitufted interneurones from layer 2/3 of the somatosensory cortex, the height and width of APs recorded at the soma are sensitive to changes in the resting membrane potential, suggesting subthreshold activity of voltage-gated conductances. Attributes of K+ currents examined in nucleated patches revealed a fast subthreshold-inactivating K+ conductance (Kf ) and a slow suprathreshold-inactivating K+ conductance (Ks ). Simulations of these K+ conductances, incorporated into a Hodgkin–Huxley-type model, suggested that during a single AP or during low frequency trains of APs, subthreshold inactivation of Kf was the primary modulator of AP shape, whereas during trains of APs the shape was governed to a larger degree by Ks resulting in the generation of smaller and broader APs. ... Compartmental simulation of the back-propagating AP suggested a mechanism for the modulation of the back-propagating AP height and width by subthreshold activation of Kf . We speculate that this signal may modulate retrograde GABA release and consequently depression of synaptic efficacy of excitatory input from neighbouring pyramidal neurones.
Reference:
1 . Korngreen A, Kaiser KM, Zilberter Y (2005) Subthreshold inactivation of voltage-gated K+ channels modulates action potentials in neocortical bitufted interneurones from rats. J Physiol 562:421-37 [PubMed]
Model Information (Click on a link to find other models with that property)
Model Type: Channel/Receptor;
Brain Region(s)/Organism:
Cell Type(s): Neocortex bitufted interneuron;
Channel(s): I K;
Gap Junctions:
Receptor(s):
Gene(s):
Transmitter(s):
Simulation Environment: NEURON;
Model Concept(s): Ion Channel Kinetics; Action Potentials;
Implementer(s): Korngreen, Alon [alon.korngreen at gmail.com];
Search NeuronDB for information about:  I K;
 
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korngreenEtAl2005
readme.txt
kfast.mod
kv.mod
mosinit.hoc
                            
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