Linked Life Data

14643462

Source:http://linkedlifedata.com/resource/pubmed/id/14643462

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
2003-12-3
pubmed:abstractText
Accumulative evidence indicates that acute (before extinction) and long-lasting (during extinction) depression can occur at excitatory synapses in mouse medial prefrontal cortex (mPFC) during re-exposure to a tone (conditioned stimulus: CS), previously paired with footshock (unconditioned stimulus: US). As recently shown, the long-term depression (LTD)-like plasticity in the mPFC does not interfere with extinction of CS-evoked freezing but predicts spontaneous recovery of this fear response. Here, the objectives were to investigate: (i). whether a resistance to extinction without any prefrontal acute synaptic plasticity could produce LTD-like changes, and (ii). by the use of paired-pulse facilitation (PPF) analyses, whether pre- or post-synaptic mechanisms were involved in this LTD phenomenon. Preliminary analyses indicated that levels of acute depression did not correlate with the degree of fear acquisition (effects of number of CS-US pairings). As a consequence, mice conditioned with 2CS+ or 2CS+/2CS- (partial reinforcement of the CS known to induce resistance to extinction) exhibited CS-associated freezing without any acute synaptic depression in the mPFC. However, during further CS-alone presentations, the 2CS+/2CS- group developed LTD-like changes that accompanied their resistance to extinguish freezing to the CS. In contrast, the 2CS+ group normally extinguished their conditioned freezing with synaptic transmission remaining at baseline levels. PPF analyses revealed that facilitation was unchanged following prefrontal LTD. These data, combined with our previous findings, (i). support a critical involvement of prefrontal LTD-like changes in spontaneous recovery of fear responses, and (ii). suggest a post-synaptic site for these changes.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0166-4328
pubmed:author
pubmed:issnType
Print
pubmed:day
30
pubmed:volume
146
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
89-96
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Behavioral and paired-pulse facilitation analyses of long-lasting depression at excitatory synapses in the medial prefrontal cortex in mice.
pubmed:affiliation
Neurosciences Cognitives, CNRS UMR 5106, Université de Bordeaux 1, Talence, France. cyril.herry@fmi.ch
pubmed:publicationType
Journal Article, Comparative Study