Integrative properties of radial oblique dendrites in hippocampal CA1 pyramidal neurons

Neuron. 2006 Apr 20;50(2):291-307. doi: 10.1016/j.neuron.2006.03.016.


Although radial oblique dendrites are a major synaptic input site in CA1 pyramidal neurons, little is known about their integrative properties. We have used multisite two-photon glutamate uncaging to deliver different spatiotemporal input patterns to single branches while simultaneously recording the uncaging-evoked excitatory postsynaptic potentials and local Ca2+ signals. Asynchronous input patterns sum linearly in spite of the spatial clustering and produce Ca2+ signals that are mediated by NMDA receptors (NMDARs). Appropriately timed and sized input patterns ( approximately 20 inputs within approximately 6 ms) produce a supralinear summation due to the initiation of a dendritic spike. The Ca2+ signals associated with synchronous input were larger and mediated by influx through both NMDARs and voltage-gated Ca2+ channels (VGCCs). The oblique spike is a fast Na+ spike whose duration is shaped by the coincident activation of NMDAR, VGCCs, and transient K+ currents. Our results suggest that individual branches can function as single integrative compartments.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Calcium Channels / metabolism
  • Dendrites / physiology*
  • Excitatory Postsynaptic Potentials / physiology
  • Glutamic Acid / metabolism
  • Patch-Clamp Techniques
  • Pyramidal Cells / physiology*
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, N-Methyl-D-Aspartate / metabolism
  • Synapses / physiology*
  • Synaptic Transmission / physiology*


  • Calcium Channels
  • Receptors, N-Methyl-D-Aspartate
  • Glutamic Acid