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

TY - JOUR

T1 - Distance-dependent gradient in NMDAR-driven spine calcium signals along tapering dendrites

AU - Walker, Alison S.

AU - Neves, Guilherme

AU - Grillo, Federico

AU - Jackson, Rachel E.

AU - Rigby, Mark

AU - O'Donnell, Cian

AU - Lowe, Andrew S.

AU - Vizcay-Barrena, Gema

AU - Fleck, Roland A.

AU - Burrone, Juan

PY - 2017/3/7

Y1 - 2017/3/7

N2 - 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.

AB - 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.

KW - Calcium

KW - Dendrite

KW - Dendritic spine

KW - Hippocampus

KW - NMDA

UR - http://www.scopus.com/inward/record.url?scp=85014726096&partnerID=8YFLogxK

U2 - 10.1073/pnas.1607462114

DO - 10.1073/pnas.1607462114

M3 - Article

AN - SCOPUS:85014726096

SN - 0027-8424

VL - 114

SP - 1986

EP - 1995

JO - Proceedings of the National Academy of Sciences of the United States of America

JF - Proceedings of the National Academy of Sciences of the United States of America

IS - 10

ER -