title: Memory Retrieval Has a Dynamic Influence on the Maintenance Mechanisms That Are Sensitive to ζ-Inhibitory Peptide (ZIP).
abstract: In neuroscientists' attempts to understand the long-term storage of memory, topics of particular importance and interest are the cellular and system mechanisms of maintenance (e.g., those sensitive to ζ-inhibitory peptide, ZIP) and those induced by memory retrieval (i.e., reconsolidation). Much is known about each of these processes in isolation, but less is known concerning how they interact. It is known that ZIP sensitivity and memory retrieval share at least some molecular targets (e.g., recycling α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid, AMPA, receptors to the plasma membrane); conversely, the fact that sensitivity to ZIP emerges only after consolidation ends suggests that consolidation (and by extension reconsolidation) and maintenance might be mutually exclusive processes, the onset of one canceling the other. Here, we use conditioned taste aversion (CTA) in rats, a cortically dependent learning paradigm, to test this hypothesis. First, we demonstrate that ZIP infusions into gustatory cortex begin interfering with CTA memory 43-45 h after memory acquisition-after consolidation ends. Next, we show that a retrieval trial administered after this time point interrupts the ability of ZIP to induce amnesia and that ZIP's ability to induce amnesia is reengaged only 45 h after retrieval. This pattern of results suggests that memory retrieval and ZIP-sensitive maintenance mechanisms are mutually exclusive and that the progression from one to the other are similar after acquisition and retrieval. They also reveal concrete differences between ZIP-sensitive mechanisms induced by acquisition and retrieval: the latency with which ZIP-sensitive mechanisms are expressed differ for the two processes.
  
  
  
  Memory retrieval and the molecular mechanisms that are sensitive to ζ-inhibitory peptide (ZIP) are the few manipulations that have been shown to effect memory maintenance. Although much is known about their effect on maintenance separately, it is unknown how they interact. Here, we describe a model for the interaction between memory retrieval and ZIP-sensitive mechanisms, showing that retrieval trials briefly (i.e., for 45 h) interrupt these mechanisms. ZIP sensitivity emerges across a similar time window after memory acquisition and retrieval; the maintenance mechanisms that follow acquisition and retrieval differ, however, in the latency with which the impact of ZIP is expressed.
authors.affiliation: Program of Neuroscience, dbkatz@brandeis.edu levitand@brandeis.edu.
authors.forename: David
authors.initials: D
authors.lastname: Levitan
authors.affiliation: Program of Neuroscience.
authors.forename: Yaihara
authors.initials: Y
authors.lastname: Fortis-Santiago
authors.affiliation: Program of Neuroscience.
authors.forename: Joshua A
authors.initials: JA
authors.lastname: Figueroa
authors.affiliation: Department of Psychology, and.
authors.forename: Emily E
authors.initials: EE
authors.lastname: Reid
authors.affiliation: Volen Center for Complex Systems, Brandeis University, Waltham, Massachusetts 02454.
authors.forename: Takashi
authors.initials: T
authors.lastname: Yoshida
authors.affiliation: Program of Neuroscience.
authors.forename: Nicholas C
authors.identifier: 0000-0003-2079-535X
authors.initials: NC
authors.lastname: Barry
authors.affiliation: Department of Psychology, and.
authors.forename: Abigail
authors.identifier: 0000-0001-7751-3355
authors.initials: A
authors.lastname: Russo
authors.affiliation: Program of Neuroscience, Department of Psychology, and Volen Center for Complex Systems, Brandeis University, Waltham, Massachusetts 02454 dbkatz@brandeis.edu levitand@brandeis.edu.
authors.forename: Donald B
authors.initials: DB
authors.lastname: Katz
mesh_terms: D000647:Amnesia / Q000139:chemically induced / Q000523:psychology; D000818:Animals; D000841:Anisomycin / Q000494:pharmacology; D001362:Avoidance Learning / Q000187:drug effects*; D057846:Cell-Penetrating Peptides; D003214:Conditioning, Classical / Q000187:drug effects; D005260:Female; D055666:Lipopeptides / Q000008:administration & dosage / Q000494:pharmacology*; D008568:Memory / Q000187:drug effects*; D011939:Mental Recall / Q000187:drug effects*; D008845:Microinjections; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D051381:Rats; D020318:Rats, Long-Evans; D013003:Somatosensory Cortex / Q000033:anatomy & histology / Q000187:drug effects; D013649:Taste / Q000187:drug effects*
chemical_list: D057846:Cell-Penetrating Peptides; D055666:Lipopeptides; D011500:Protein Synthesis Inhibitors; C568285:zeta-inhibitory peptide; D000841:Anisomycin
keywords: ZIP; consolidation; memory; reconsolidation; retrieval