%0 Journal Article
%A Sánchez-Aguilera López, Alberto
%A Sánchez Alonso, José Luis
%A Vicente Torres, María Ángeles
%A Colino Matilla, María Asunción
%T A novel short-term plasticity of intrinsic excitability in the hippocampal CA1 pyramidal cells
%D 2014
%@ 0022-3751
%U https://hdl.handle.net/20.500.14352/94837
%X Changes in neuronal activity often trigger compensatory mechanisms aimed at regulating network activity homeostatically. Here we have identified and characterized a novel form of compensatory short-term plasticity of membrane excitability, which develops early after the eye-opening period in rats (P16–19 days) but not before that developmental stage (P9–12 days old). Holding the membrane potential of CA1 neurons right below the firing threshold from 15 s to several minutes induced a potentiation of the repolarizing phase of the action potentials that contributed to a decrease in the firing rate of CA1 pyramidal neurons in vitro. Furthermore, the mechanism for inducing this plasticity required the action of intracellular Ca2+ entering through T-type Ca2+ channels. This increase in Ca2+ subsequently activated the Ca2+ sensor K+ channel interacting protein 3, which led to the increase of an A-type K+ current. These results suggest that Ca2+ modulation of somatic A-current represents a new form of homeostatic regulation that provides CA1 pyramidal neurons with the ability to preserve their firing abilities in response to membrane potential variations on a scale from tens of seconds to several minutes.
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