A Septin-Dependent Diffusion Barrier at Dendritic Spine Necks.
PLoS ONE. 2014-12-10; 9(12): e113916
DOI: 10.1371/journal.pone.0113916
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1. PLoS One. 2014 Dec 10;9(12):e113916. doi: 10.1371/journal.pone.0113916.
eCollection 2014.
A Septin-Dependent Diffusion Barrier at Dendritic Spine Necks.
Ewers H(1), Tada T(2), Petersen JD(1), Racz B(3), Sheng M(2), Choquet D(1).
Author information:
(1)Université de Bordeaux, Interdisciplinary Institute for Neuroscience, UMR
5297, F-33000 Bordeaux, France; CNRS, Interdisciplinary Institute for
Neuroscience, UMR 5297, F-33000 Bordeaux, France.
(2)The Picower Institute for Learning and Memory, Departments of Brain and
Cognitive Sciences and Biology, Massachusetts Institute of Technology, Cambridge,
MA 02446, United States of America.
(3)Department of Anatomy and Histology, Faculty of Veterinary Science, Szent
István University, 1078 Budapest, Hungary.
Excitatory glutamatergic synapses at dendritic spines exchange and modulate their
receptor content via lateral membrane diffusion. Several studies have shown that
the thin spine neck impedes the access of membrane and solute molecules to the
spine head. However, it is unclear whether the spine neck geometry alone
restricts access to dendritic spines or if a physical barrier to the diffusion of
molecules exists. Here, we investigated whether a complex of septin cytoskeletal
GTPases localized at the base of the spine neck regulates diffusion across the
spine neck. We found that, during development, a marker of the septin complex,
Septin7 (Sept7), becomes localized to the spine neck where it forms a stable
structure underneath the plasma membrane. We show that diffusion of receptors and
bulk membrane, but not cytoplasmic proteins, is slower in spines bearing Sept7 at
their neck. Finally, when Sept7 expression was suppressed by RNA interference,
membrane molecules explored larger membrane areas. Our findings indicate that
Sept7 regulates membrane protein access to spines.
DOI: 10.1371/journal.pone.0113916
PMCID: PMC4262254
PMID: 25494357 [Indexed for MEDLINE]