In vivo dendritic calcium dynamics in deep-layer cortical pyramidal neurons

Nat Neurosci. 1999 Nov;2(11):989-96. doi: 10.1038/14788.


Dendritic Ca2+ action potentials in neocortical pyramidal neurons have been characterized in brain slices, but their presence and role in the intact neocortex remain unclear. Here we used two-photon microscopy to demonstrate Ca2+ electrogenesis in apical dendrites of deep-layer pyramidal neurons of rat barrel cortex in vivo. During whisker stimulation, complex spikes recorded intracellularly from distal dendrites and sharp waves in the electrocorticogram were accompanied by large dendritic [Ca2+ ] transients; these also occurred during bursts of action potentials recorded from somata of identified layer 5 neurons. The amplitude of the [Ca 2+] transients was largest proximal to the main bifurcation, where sodium action potentials produced little Ca2+ influx. In some cases, synaptic stimulation evoked [Ca2+] transients without a concomitant action potential burst, suggesting variable coupling between dendrite and soma.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Action Potentials / physiology
  • Animals
  • Calcium / metabolism*
  • Cerebral Cortex / metabolism*
  • Dendrites / metabolism*
  • In Vitro Techniques
  • Pyramidal Cells / metabolism*
  • Rats
  • Rats, Sprague-Dawley


  • Calcium