title: Dynamic distribution of endoplasmic reticulum in hippocampal neuron dendritic spines.
abstract: The role of the endoplasmic reticulum (ER) localized in dendritic spines has become a subject of intense interest because of its potential functions in local protein synthesis and signal transduction. Although it is recognized from electron microscopic studies that not all spines contain ER, little is know of its dynamic regulation or turnover. Here, we report a surprising degree of turnover of ER within spines. Using confocal microscopy imaging we observed continuity of spine-ER with dendritic ER in hippocampal primary neurons. Over 24 h, less than 50% of spine ER was stable. Despite this high degree of turn over, we identified a significant subset of spines that maintained ER for at least 4 days. These results indicate that within a single neuron, the organelle composition of a spine is unexpectedly dynamic and may explain aspects of the spine-to-spine variation in calcium spike magnitude and localized protein synthesis and trafficking.
authors.affiliation: Division of Neuroscience, College of Medicine and Veterinary Medicine, University of Edinburgh, 1 George Square, Edinburgh, UK. hakan.toresson@med.lu.se
authors.forename: Håkan
authors.initials: H
authors.lastname: Toresson
authors.forename: Seth G N
authors.initials: SG
authors.lastname: Grant
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D049229:Dendritic Spines / Q000502:physiology*; D003952:Diagnostic Imaging; D000076122:Disks Large Homolog 4 Protein; D004622:Embryo, Mammalian; D004721:Endoplasmic Reticulum / Q000502:physiology*; D005260:Female; D049452:Green Fluorescent Proteins / Q000378:metabolism; D051528:Guanylate Kinases; D006624:Hippocampus / Q000166:cytology*; D007150:Immunohistochemistry / Q000379:methods; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D051379:Mice; D009474:Neurons / Q000166:cytology*; D011247:Pregnancy; D016708:Synaptophysin / Q000378:metabolism; D013997:Time Factors; D014162:Transfection / Q000379:methods
chemical_list: D000076122:Disks Large Homolog 4 Protein; C501447:Dlg4 protein, mouse; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D016708:Synaptophysin; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D051528:Guanylate Kinases