title: Early versus late-phase consolidation of opiate reward memories requires distinct molecular and temporal mechanisms in the amygdala-prefrontal cortical pathway.
abstract: The consolidation of newly acquired memories involves the temporal transition from a recent, less stable trace to a more permanent consolidated form. Opiates possess potent rewarding effects and produce powerful associative memories. The activation of these memories is associated with opiate abuse relapse phenomena and the persistence of compulsive opiate dependence. However, the neuronal, molecular and temporal mechanisms by which associative opiate reward memories are consolidated are not currently understood. We report that the consolidation of associative opiate reward memories involves a temporal and molecular switch between the basolateral nucleus of the amygdala (BLA) (early consolidation phase) to the medial prefrontal cortex (mPFC) (late consolidation phase). We demonstrate at the molecular, behavioral and neuronal levels that the consolidation of a recently acquired opiate reward memory involves an extracellular signal-related kinase (ERK)-dependent phosphorylation process within the BLA. In contrast, later-stage consolidation of a newly acquired memory is dependent upon a calcium-calmodulin-dependent (CaMKII), ERK-independent, mechanism in the mPFC, over a 12 hr temporal gradient. In addition, using in vivo multi-unit neuronal recordings in the mPFC, we report that protein synthesis within the BLA modulates the consolidation of opiate-reward memory in neuronal mPFC sub-populations, via the same temporal dynamic.
authors.affiliation: Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada.
authors.forename: Shervin
authors.initials: S
authors.lastname: Gholizadeh
authors.forename: Ninglei
authors.initials: N
authors.lastname: Sun
authors.forename: Xavier
authors.initials: X
authors.lastname: De Jaeger
authors.forename: Melanie
authors.initials: M
authors.lastname: Bechard
authors.forename: Lique
authors.initials: L
authors.lastname: Coolen
authors.forename: Steven R
authors.initials: SR
authors.lastname: Laviolette
mesh_terms: D000679:Amygdala / Q000187:drug effects* / Q000378:metabolism*; D000701:Analgesics, Opioid / Q000494:pharmacology*; D000818:Animals; D008297:Male; D008568:Memory / Q000187:drug effects / Q000502:physiology*; D017397:Prefrontal Cortex / Q000187:drug effects / Q000502:physiology*; D051381:Rats
chemical_list: D000701:Analgesics, Opioid