Pansynaptic enlargement at adult cortical connections strengthened by experience
File(s)
Author(s)
Cheetham, Claire EJ
Barnes, Samuel J
Albieri, Giorgia
Knott, Graham W
Finnerty, Gerald T
Type
Journal Article
Abstract
Behavioral experience alters the strength of neuronal connections in adult neocortex. These changes in synaptic strength are thought to be central to experience-dependent plasticity, learning, and memory. However, it is not known how changes in synaptic transmission between neurons become persistent, thereby enabling the storage of previous experience. A long-standing hypothesis is that altered synaptic strength is maintained by structural modifications to synapses. However, the extent of synaptic modifications and the changes in neurotransmission that the modifications support remain unclear. To address these questions, we recorded from pairs of synaptically connected layer 2/3 pyramidal neurons in the barrel cortex and imaged their contacts with high-resolution confocal microscopy after altering sensory experience by whisker trimming. Excitatory connections strengthened by experience exhibited larger axonal varicosities, dendritic spines, and interposed contact zones. Electron microscopy showed that contact zone size was strongly correlated with postsynaptic density area. Therefore, our findings indicate that whole synapses are larger at strengthened connections. Synaptic transmission was both stronger and more reliable following experience-dependent synapse enlargement. Hence, sensory experience modified both presynaptic and postsynaptic function. Our findings suggest that the enlargement of synaptic contacts is an integral part of long-lasting strengthening of cortical connections and, hence, of information storage in the neocortex.
Date Issued
2014-02-01
Date Acceptance
2012-10-01
Citation
Cerebral Cortex, 2014, 24 (2), pp.521-531
ISSN
1047-3211
Publisher
Oxford University Press (OUP)
Start Page
521
End Page
531
Journal / Book Title
Cerebral Cortex
Volume
24
Issue
2
Copyright Statement
© The Author 2012. Published by Oxford University Press.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by-nc/3.0/), which permits non-commercial reuse, distribution, and reproduction in any medium, provided the original work is properly cited. For commercial re-use, please contact journals.permissions@oup.com.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by-nc/3.0/), which permits non-commercial reuse, distribution, and reproduction in any medium, provided the original work is properly cited. For commercial re-use, please contact journals.permissions@oup.com.
License URL
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000329840900023&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Subjects
Science & Technology
Life Sciences & Biomedicine
Neurosciences
Neurosciences & Neurology
barrel cortex
confocal microscopy
electrophysiology
experience-dependent plasticity
structural plasticity
LONG-TERM POTENTIATION
HIPPOCAMPAL CA1 SYNAPSES
SINGLE DENDRITIC SPINES
SOMATIC SENSORY CORTEX
SMALL PYRAMIDAL NEURON
RAT CEREBRAL CORTEX
NEOCORTEX IN-VIVO
SYNAPTIC PLASTICITY
MORPHOLOGICAL-CHANGES
EXCITATORY SYNAPSES
Publication Status
Published
Date Publish Online
2012-10-31