"... we measured T-type current of isolated goldfish retinal ganglion cells with perforated-patch voltageclamp methods in solutions containing a normal extracellular Ca2+ concentration. The voltage sensitivities and rates of current activation, inactivation, deactivation, and recovery from inactivation were similar to those of expressed +1G (CaV3.1) Ca2+ channel clones, except that the rate of deactivation was significantly faster. We reproduced the amplitude and kinetics of measured T currents with a numerical simulation based on a kinetic model developed for an +1G Ca2+ channel. Finally, we show that this model predicts the increase of T-type current made available between resting potential and spike threshold by repetitive hyperpolarizations presented at rates that are within the bandwidth of signals processed in situ by these neurons."
Model Type: Neuron or other electrically excitable cell; Channel/Receptor
Region(s) or Organism(s): Retina
Cell Type(s): Retina ganglion GLU cell
Currents: I T low threshold
Genes: Cav3.1 CACNA1G
Model Concept(s): Ion Channel Kinetics
Simulation Environment: NEURON
Implementer(s): Hayashida, Yuki [yukih at cs.kumamoto-u.ac.jp]
References:
Lee SC, Hayashida Y, Ishida AT. (2003). Availability of low-threshold Ca2+ current in retinal ganglion cells. Journal of neurophysiology. 90 [PubMed]