Distance-dependent gradient in NMDAR-driven spine calcium signals along tapering dendrites

Proc Natl Acad Sci U S A. 2017 Mar 7;114(10):E1986-E1995. doi: 10.1073/pnas.1607462114. Epub 2017 Feb 16.


Neurons receive a multitude of synaptic inputs along their dendritic arbor, but how this highly heterogeneous population of synaptic compartments is spatially organized remains unclear. By measuring N-methyl-d-aspartic acid receptor (NMDAR)-driven calcium responses in single spines, we provide a spatial map of synaptic calcium signals along dendritic arbors of hippocampal neurons and relate this to measures of synapse structure. We find that quantal NMDAR calcium signals increase in amplitude as they approach a thinning dendritic tip end. Based on a compartmental model of spine calcium dynamics, we propose that this biased distribution in calcium signals is governed by a gradual, distance-dependent decline in spine size, which we visualized using serial block-face scanning electron microscopy. Our data describe a cell-autonomous feature of principal neurons, where tapering dendrites show an inverse distribution of spine size and NMDAR-driven calcium signals along dendritic trees, with important implications for synaptic plasticity rules and spine function.

Keywords: NMDA; calcium; dendrite; dendritic spine; hippocampus.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Calcium / metabolism*
  • Calcium Signaling
  • Dendritic Spines / metabolism*
  • Dendritic Spines / ultrastructure
  • Embryo, Mammalian
  • Female
  • Gene Expression
  • Hippocampus / cytology
  • Hippocampus / metabolism*
  • Mice
  • Mice, Inbred C57BL
  • Microscopy, Electron
  • Microtomy
  • N-Methylaspartate / metabolism
  • Neuronal Plasticity
  • Pregnancy
  • Primary Cell Culture
  • Pyramidal Cells / metabolism*
  • Pyramidal Cells / ultrastructure
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, N-Methyl-D-Aspartate / genetics
  • Receptors, N-Methyl-D-Aspartate / metabolism*
  • Synapses / physiology


  • Receptors, N-Methyl-D-Aspartate
  • N-Methylaspartate
  • Calcium