Premium
Posttraining but not pretraining lesions of the hippocampus interfere with feature‐negative discrimination of fear‐potentiated startle
Author(s) -
Heldt Scott A.,
Coover Gary D.,
Falls William A.
Publication year - 2002
Publication title -
hippocampus
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.767
H-Index - 155
eISSN - 1098-1063
pISSN - 1050-9631
DOI - 10.1002/hipo.10033
Subject(s) - psychology , hippocampal formation , fear potentiated startle , hippocampus , neuroscience , lesion , fear conditioning , startle response , stimulus (psychology) , feature (linguistics) , extinction (optical mineralogy) , cognitive psychology , amygdala , chemistry , linguistics , philosophy , psychiatry , mineralogy
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. Pretraining 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. Hippocampus 2002;12:774–786. © 2002 Wiley‐Liss, Inc.