Unbound MEDLINE

A metaplasticity-like mechanism supports the selection of fear memories: role of protein kinase a in the amygdala.

Abstract

How the brain determines which memories are selected for long-term storage is critical for a full understanding of memory. One possibility is that memories are selected based on the history of activity and current state of neurons within a given memory circuit. Many in vitro studies have demonstrated metaplasticity-like effects whereby prior neuronal activity can affect the ability of cells to express synaptic plasticity in the future; however, the significance of these findings to memory is less clear. Here we show in rats that a single pairing of a light with shock, insufficient to support either short- or long-term fear memory, primes future learning such that another trial delivered within a circumscribed time window lasting from ∼60 min to 3 d results in the formation of a long-lasting and robust fear memory. Two adequately spaced training trials support long-term fear memory only if the two trials are signaled by the same cue. Furthermore, although a single training trial does not support formation of an observable fear memory, it does result in the phosphorylation of several targets of protein kinase A (PKA) in the amygdala. Accordingly, blocking PKA signaling in the amygdala before the first training trial completely prevents the ability of that trial to facilitate the formation of long-term fear memory when a second trial is delivered 24 h later. These findings may provide insight into how memories are selected for long-term storage.

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    • Authors

    Parsons RG, Davis M

    Institution

    Department of Psychiatry and Behavioral Sciences, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia 30329, USA. rparso3@emory.edu

    Source

    The Journal of neuroscience : the official journal of the Society for Neuroscience 32:23 2012 Jun 6 pg 7843-51

    MeSH

    Amygdala
    Animals
    Behavior, Animal
    Blotting, Western
    Cues
    Cyclic AMP
    Cyclic AMP-Dependent Protein Kinases
    Electroshock
    Fear
    Learning
    Male
    Memory
    Memory, Long-Term
    Neuronal Plasticity
    Protein Kinase Inhibitors
    Rats
    Rats, Sprague-Dawley
    Startle Reaction
    Thionucleotides

    Pub Type(s)

    Journal Article
    Research Support, N.I.H., Extramural
    Research Support, Non-U.S. Gov't

    Language

    eng

    PubMed ID

    22674260