Arc reactivity in accumbens nucleus, amygdala and hippocampus differentiates cue over context responses during reactivation of opiate withdrawal memory.
Neurobiology of Learning and Memory. 2019-02-13; 159: 24-35
DOI: 10.1016/j.nlm.2019.02.007
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Opiate withdrawal induces an early aversive state which can be associated to
contexts and/or cues, and re-exposure to either these contexts or cues may
participate in craving and relapse. Nucleus accumbens (NAC), hippocampus (HPC)
and basolateral amygdala (BLA) are crucial substrates for acute opiate
withdrawal, and for withdrawal memory retrieval. Also HPC and BLA interacting
with the NAC are suggested to respectively mediate the processing of context and
cue representations of drug-related memories. Here we used a paradigm of
conditioned suppression of operant food seeking, allowing to differentiate
context and cue related responses, to study the influence of withdrawal memories
on operant behavior and the underlying neural substrates. catFISH for Arc mRNA
expression was used to discriminate cellular responses during context and cue
(flashing light) periods in this paradigm. We show that reactivation of the
memory of the negative affective state of withdrawal suppresses active lever
pressing for food, and this conditioned suppression is generalized to the
context. Interestingly the behavioral responses during the context and cue light
periods are associated with differential Arc mRNA activations within the NAC,
BLA, and HPC. Indeed both periods led to NAC shell activation whereas the NAC
core was responsive only following the cue light period. Moreover, BLA and HPC
were more responsive during cue-light and context period respectively. These data
further support the already reported differential role of these brain structures
on cue vs context-induced reinstatement of operant behaviors, and highlight the
existence of common mechanisms for the processing of positive and aversive
emotional memories.
Copyright © 2019. Published by Elsevier Inc.
DOI: 10.1016/j.nlm.2019.02.007
PMID: 30771462