Determinants of voltage attenuation in neocortical pyramidal neuron dendrites

Greg Stuart, Nelson Spruston

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395 Citations (Scopus)

Abstract

How effectively synaptic and regenerative potentials propagate within neurons depends critically on the membrane properties and intracellular resistivity of the dendritic tree. These properties therefore are important determinants of neuronal function. Here we use simultaneous whole-cell patch- pipette recordings from the soma and apical dendrite of neocortical layer 5 pyramidal neurons to directly measure voltage attenuation in cortical neurons. When combined with morphologically realistic compartmental models of the same cells, the data suggest that the intracellular resistivity of neocortical pyramidal neurons is relatively low (~70 to 100 Ωcm), but that voltage attenuation is substantial because of nonuniformly distributed resting conductances present at a higher density in the distal apical dendrites. These conductances, which were largely blocked by bath application of CsCI (5 mu), significantly increased steady-state voltage attenuation and decreased EPSP integral and peak in a manner that depended on the location of the synapse. Together these findings suggest that nonuniformly distributed Cs-sensitive and -insensitive resting conductances generate a 'leaky' apical dendrite, which differentially influences the integration of spatially segregated synaptic inputs.

Original languageEnglish
Pages (from-to)3501-3510
Number of pages10
JournalJournal of Neuroscience
Volume18
Issue number10
DOIs
Publication statusPublished - 15 May 1998
Externally publishedYes

Keywords

  • Cesium
  • Dendrite
  • Hyperpolarization-activated conductance
  • I(h)
  • Intracellular resistivity
  • Neocortical pyramidal neuron
  • Sag
  • Voltage attenuation

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