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Involvement of the insular cortex in the consolidation and expression of contextual fear conditioning
Author(s) -
Alves Fernando H. F.,
Gomes Felipe V.,
Reis Daniel G.,
Crestani Carlos C.,
Corrêa Fernando M. A.,
Guimarães Francisco S.,
Resstel Leonardo B. M.
Publication year - 2013
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1111/ejn.12210
Subject(s) - fear conditioning , conditioning , memory consolidation , psychology , heart rate , classical conditioning , aversive stimulus , neuroscience , freezing behavior , extinction (optical mineralogy) , context (archaeology) , insular cortex , stimulus (psychology) , anesthesia , medicine , blood pressure , amygdala , chemistry , hippocampus , cognitive psychology , biology , paleontology , statistics , mineralogy , mathematics
The insular cortex ( IC ) has been reported to be involved in the modulation of memory and autonomic and defensive responses. However, there is conflicting evidence about the role of the IC in fear conditioning. To explore the IC involvement in both behavioral and autonomic responses induced by contextual fear conditioning, we evaluated the effects of the reversible inhibition of the IC neurotransmission through bilateral microinjections of the non‐selective synapse blocker C o C l 2 (1 m m ) 10 min before or immediately after the conditioning session or 10 min before re‐exposure to the aversive context. In the conditioning session, rats were exposed to a footshock chamber (context) and footshocks were used as the unconditioned stimulus. Forty‐eight hours later, the animals were re‐exposed to the aversive context for 10 min, but no shock was given. Behavioral (freezing) as well as cardiovascular (arterial pressure and heart rate increases) responses induced by re‐exposure to the aversive context were analysed. It was observed that the local IC neurotransmission inhibition attenuated freezing and the mean arterial pressure and heart rate increase of the groups that received the C o C l 2 either immediately after conditioning or 10 min before re‐exposure to the aversive context, but not when the C o C l 2 was injected before the conditioning session. These findings suggest the involvement of the IC in the consolidation and expression of contextual aversive memory. However, the IC does not seem to be essential for the acquisition of memory associated with aversive context.