Differential distribution of NCX1 contributes to spine-dendrite compartmentalization in CA1 pyramidal cells.
Compartmentalization of Ca(2+) between dendritic spines and shafts is governed by diffusion barriers and a range of Ca(2+) extrusion mechanisms. The distinct contribution of different Ca(2+) clearance systems to Ca(2+) compartmentalization in dendritic spines versus shafts remains elusive. We applied a combination of ultrastructural and functional imaging methods to assess the subcellular distribution and role of NCX1 in rat CA1 pyramidal cells. Quantitative electron microscopic analysis of preembedding immunogold reactions revealed uniform densities of NCX1 along the shafts of apical and basal dendrites, but densities in dendritic shafts were approximately seven times higher than in dendritic spines. In line with these results, two-photon imaging of synaptically activated Ca(2+) transients during NCX blockade showed preferential action localized to the dendritic shafts for NCXs in regulating spine-dendrite coupling.
Lörincz
Andrea
A
Department of Comparative Physiology, University of Szeged, Közép fasor 52, 6726 Szeged, Hungary.
Rózsa
Balázs
B
Katona
Gergely
G
Vizi
E Sylvester
ES
Tamás
Gábor
G
D000818:Animals; D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling; D002451:Cell Compartmentation; D003712:Dendrites / Q000378:metabolism*; D004594:Electrophysiology; D006624:Hippocampus / Q000378:metabolism; D007150:Immunohistochemistry; D046529:Microscopy, Electron, Transmission; D019579:Neocortex / Q000378:metabolism; D017966:Pyramidal Cells / Q000166:cytology* / Q000378:metabolism*; D051381:Rats; D012964:Sodium / Q000378:metabolism; D019831:Sodium-Calcium Exchanger / Q000378:metabolism*; D013569:Synapses / Q000378:metabolism
D019831:Sodium-Calcium Exchanger; C110374:sodium-calcium exchanger 1; D012964:Sodium; D002118:Calcium