Low-threshold potassium channels and a low-threshold calcium channel regulate Ca2+ spike firing in the dendrites of cerebellar Purkinje neurons: a modeling study

Brain Res. 2001 Feb 9;891(1-2):106-15. doi: 10.1016/s0006-8993(00)03206-6.


Various types of voltage-gated ion channels are distributed along the dendrites of neurons in the central nervous system. We have recently shown experimentally that the dendrites of cerebellar Purkinje neurons contain low-threshold voltage-gated Ca(2+) channels and low-threshold voltage-gated K+ channels. Although we found that these channels are involved in regulating the onset of Ca(2+)-dependent action potentials in the dendrites, we were unable to identify which of the known types of low-threshold Ca2+ channels and K+ channels were responsible, since there was no reliable method of discriminating between them. Here, we have built a detailed compartmental model of a Purkinje neuron by incorporating two types of low-threshold Ca2+ channel (T-type and class-E, or R-type) and two types of low-threshold K+ channel (A-type and D-type), in addition to another eight voltage-gated channel types, using a compartmental model neuron simulator. The model reproduces the basic features of the depolarization-induced responses of Purkinje neurons, such as fast Na+ spikes in the soma, Ca2+ spikes in the dendrites, the slow onset of Ca2+ spikes, repetitive Ca2+ spikes in the presence of TTX, the marked shortening of Ca2+ spike onset in the presence of 4-aminopydridine, and the longer Ca2+ spike onset in the presence of Ni2+. Our model shows that the D-type K+ channel and the class-E Ca2+ channel regulate the onset of depolarization-induced Ca2+ spikes in Purkinje neurons. These channels might be involved in integrating synaptic inputs in Purkinje neurons.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Action Potentials / drug effects
  • Action Potentials / physiology*
  • Animals
  • Calcium / metabolism
  • Calcium Channels / drug effects
  • Calcium Channels / metabolism*
  • Calcium Signaling / drug effects
  • Calcium Signaling / physiology*
  • Dendrites / drug effects
  • Dendrites / metabolism*
  • Dendrites / ultrastructure
  • Male
  • Models, Neurological*
  • Nickel / pharmacology
  • Potassium Channels / drug effects
  • Potassium Channels / metabolism*
  • Purkinje Cells / cytology
  • Purkinje Cells / drug effects
  • Purkinje Cells / metabolism*
  • Rats
  • Reproducibility of Results
  • Tetrodotoxin / pharmacology
  • Time Factors


  • Calcium Channels
  • Potassium Channels
  • Tetrodotoxin
  • Nickel
  • Calcium