Document Detail

Posttraining but not pretraining lesions of the hippocampus interfere with feature-negative discrimination of fear-potentiated startle.
MedLine Citation:
PMID:  12542229     Owner:  NLM     Status:  MEDLINE    
Previous studies have suggested that the hippocampus may play an important role in some forms of inhibitory learning. The goal of the present study was to assess whether the hippocampus is also important for inhibition of fear acquired after serial feature-negative discrimination training. Rats were given aspiration lesions of the hippocampus either before or after training in which a target light was paired with shock when presented alone, but not paired with shock when presented in serial compound with a noise feature (light+/noise-->light-). Conditioned fear to the target stimulus and feature-target compound were measured with fear-potentiated startle. Pre-training lesion of the hippocampus did not disrupt feature-negative discrimination performance relative to sham-operated and cortical lesioned controls. In contrast, hippocampal lesions performed after training severely disrupted performance. Specifically, rats with hippocampal lesions failed to inhibit fear when the noise feature was presented in compound with the target. However, these rats could reacquire the feature-negative discrimination. These observations suggest that the hippocampus may normally be involved in retention or retrieval of serial feature-negative discrimination; however, in its absence feature-negative discrimination can still be acquired.
Scott A Heldt; Gary D Coover; William A Falls
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Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Hippocampus     Volume:  12     ISSN:  1050-9631     ISO Abbreviation:  Hippocampus     Publication Date:  2002  
Date Detail:
Created Date:  2003-01-24     Completed Date:  2003-03-21     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  9108167     Medline TA:  Hippocampus     Country:  United States    
Other Details:
Languages:  eng     Pagination:  774-86     Citation Subset:  IM    
Department of Psychology, Northern Illinois University, DeKalb, Illinois 60115, USA.
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MeSH Terms
Acoustic Stimulation
Avoidance Learning / physiology*
Conditioning (Psychology) / physiology
Discrimination Learning / physiology*
Fear / physiology*
Hippocampus / injuries,  physiopathology*,  surgery
Learning Disorders / pathology,  physiopathology*
Memory Disorders / pathology,  physiopathology*
Neocortex / injuries,  physiopathology,  surgery
Neural Pathways / injuries,  physiopathology,  surgery
Photic Stimulation
Rats, Sprague-Dawley
Startle Reaction / physiology*
Grant Support

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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