UNIGE document Scientific Article
previous document  unige:10463  next document
add to browser collection

Remodeling of synaptic membranes after induction of long-term potentiation

Nikonenko, Irina
Povilaitite, P.
Parisi, Lorena
Published in The Journal of neuroscience. 2001, vol. 21, no. 16, p. 6245-6251
Abstract Several morphological changes of synapses have been reported to be associated with the induction of long-term potentiation (LTP) in the CA1 hippocampus, including an transient increase in the proportion of synapses with perforated postsynaptic densities (PSDs) and a later occurrence of multiple spine boutons (MSBs) in which the two spines arise from the same dendrite. To investigate the functional significance of these modifications, we analyzed single sections and reconstructed 134 synapses labeled via activity using a calcium precipitation approach. Analyses of labeled spine profiles showed changes of the spine head area, PSD length, and proportion of spine profiles containing a coated vesicle that reflected variations in the relative proportion of different types of synapses. Three-dimensional reconstruction indicated that the increase of perforated spine profiles observed 30 min after LTP induction essentially resulted from synapses exhibiting segmented, completely partitioned PSDs. These synapses had spine head and PSD areas approximately three times larger than those of simple synapses. They contained coated vesicles in a much higher proportion than that of any other type of synapse and exhibited large spinules associated with the PSD. Also the MSBs with two spines arising from the same dendrite that were observed 1-2 hr after LTP induction included a spine that was smaller and a PSD that was smaller than those of simple synapses. These results support the idea that LTP induction is associated with an enhanced recycling of synaptic membrane and that this process could underlie the formation of synapses with segmented PSDs and eventually result in the formation of a new, immature spine.
Keywords AnimalsCalcium/metabolismCell Surface Extensions/metabolism/ ultrastructureCoated Vesicles/ultrastructureDendrites/metabolism/ultrastructureElectric StimulationHippocampus/metabolism/ultrastructureLong-Term Potentiation/ physiologyMicroscopy, ElectronNeuronal Plasticity/physiologyRatsSynapses/metabolism/ ultrastructureSynaptic Membranes/metabolism/ ultrastructure
PMID: 11487647
Full text
Article - document accessible for UNIGE members only Limited access to UNIGE
Other version: http://www.jneurosci.org/cgi/reprint/21/16/6245.pdf
(ISO format)
TONI, Nicolas et al. Remodeling of synaptic membranes after induction of long-term potentiation. In: The Journal of neuroscience, 2001, vol. 21, n° 16, p. 6245-6251. https://archive-ouverte.unige.ch/unige:10463

460 hits

0 download


Deposited on : 2010-08-06

Export document
Format :
Citation style :