Linked Life Data

15669102

Source:http://linkedlifedata.com/resource/pubmed/id/15669102

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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2005-6-1
pubmed:abstractText
Hippocampal and amygdaloid neuroplasticity are important substrates for Pavlovian fear conditioning. The hippocampus has been implicated in trace fear conditioning. However, a systematic investigation of the significance of the trace interval has not yet been performed. Therefore, this study analyzed the time-dependent involvement of N-methyl-D-aspartate (NMDA) receptors in the dorsal hippocampus in one-trial auditory trace fear conditioning in C57BL/6J mice. The NMDA receptor antagonist APV was injected bilaterally into the dorsal hippocampus 15 min before training. Mice were exposed to tone (conditioned stimulus [CS]) and footshock (unconditioned stimulus [US]) in the conditioning context without delay (0 s) or with CS-US (trace) intervals of 1-45 s. Conditioned auditory fear was determined 24 h after training by the assessment of freezing and computerized evaluation of inactivity in a new context; 2 h later, context-dependent memory was tested in the conditioning context. NMDA receptor blockade by APV markedly impaired conditioned auditory fear at trace intervals of 15 s and 30 s, but not at shorter trace intervals. A 45-s trace interval prevented the formation of conditioned tone-dependent fear. Context-dependent memory was always impaired by APV treatment independent of the trace interval. The results indicate that the dorsal hippocampus and its NMDA receptors play an important role in auditory trace fear conditioning at trace intervals of 15-30-s length. In contrast, NMDA receptors in the dorsal hippocampus are unequivocally involved in contextual fear conditioning independent of the trace interval. The results point at a time-dependent role of the dorsal hippocampus in encoding of noncontingent explicit stimuli. Preprocessing of long CS-US contingencies in the hippocampus appears to be important for the final information processing and execution of fear memories through amygdala circuits.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
1050-9631
pubmed:author
pubmed:copyrightInfo
(c) 2005 Wiley-Liss, Inc.
pubmed:issnType
Print
pubmed:volume
15
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
418-26
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:15669102-2-Amino-5-phosphonovalerate, pubmed-meshheading:15669102-Acoustic Stimulation, pubmed-meshheading:15669102-Amygdala, pubmed-meshheading:15669102-Animals, pubmed-meshheading:15669102-Conditioning (Psychology), pubmed-meshheading:15669102-Cues, pubmed-meshheading:15669102-Excitatory Amino Acid Antagonists, pubmed-meshheading:15669102-Fear, pubmed-meshheading:15669102-Glutamic Acid, pubmed-meshheading:15669102-Hippocampus, pubmed-meshheading:15669102-Learning, pubmed-meshheading:15669102-Male, pubmed-meshheading:15669102-Memory, pubmed-meshheading:15669102-Mice, pubmed-meshheading:15669102-Mice, Inbred C57BL, pubmed-meshheading:15669102-Neural Pathways, pubmed-meshheading:15669102-Neuronal Plasticity, pubmed-meshheading:15669102-Receptors, N-Methyl-D-Aspartate, pubmed-meshheading:15669102-Synaptic Transmission, pubmed-meshheading:15669102-Time Factors
pubmed:year
2005
pubmed:articleTitle
Time-dependent involvement of the dorsal hippocampus in trace fear conditioning in mice.
pubmed:affiliation
Department of Molecular Neuroendocrinology, Max Planck Institute for Experimental Medicine, Goettingen, Germany. ilga.misane@usask.ca
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't