Ca2+-induced Ca2+ release supports the relay mode of activity in thalamocortical cells

Neuron. 2000 May;26(2):483-92. doi: 10.1016/s0896-6273(00)81180-0.


Ca2+ ions play an important role during rhythmic bursting of thalamocortical neurons within sleep. The function of Ca2+ during the tonic relay mode of these neurons during wakefulness is less clear. Here, we report that tonic activity in thalamocortical cells results in an increase in the intracellular Ca2+ concentration and subsequent release of Ca2+ from intracellular stores mediated via ryanodine receptors (RyRs). Blockade of Ca2+ release shifted the regular firing of single action potentials toward the generation of spike clusters. Regular spike firing and intracellular Ca2+ release thus appear to be functionally coupled in a positive feedback manner, thereby supporting the relay mode of thalamocortical cells during wakefulness. Regulatory influences may be coupled to this system via the cyclic ADP ribose pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Action Potentials / physiology
  • Animals
  • Calcium / metabolism*
  • Calcium / pharmacology*
  • Cerebral Cortex / cytology
  • Cerebral Cortex / physiology*
  • In Vitro Techniques
  • Intracellular Membranes / metabolism
  • Nerve Tissue Proteins / physiology
  • Osmolar Concentration
  • Rats
  • Rats, Long-Evans
  • Ryanodine Receptor Calcium Release Channel / physiology
  • Thalamus / cytology
  • Thalamus / physiology*


  • Nerve Tissue Proteins
  • Ryanodine Receptor Calcium Release Channel
  • Calcium