Effects of the Protein Synthesis Inhibitor Cycloheximide or the β-Adrenergic Antagonist Propranolol on Reconsolidation of Spatial Memory or Auditory Fear Conditioning, Respectively, in Adolescent Rats

Memory reconsolidation, or the concept that an old previously consolidated memory must undergo reconsolidation following retrieval from long-term memory, has received considerable attention over the last decade. Relatively little evidence, however, has examined this phenomenon in developmentally immature organisms, and even fewer studies have considered a state-dependent retrieval explanation for amnesias associated with disruption of reconsolidation processes. Here we report the results of two experiments using adolescent rats and a state-dependent design. In Experiment 1, animals acquired a spatial memory in the Morris water maze, but failed to show any sign of reconsolidation impairment or state-dependency using the protein synthesis inhibitor cycloheximide. In Experiment 2, animals were given auditory fear conditioning, but also did not show any evidence of a reconsolidation impairment or state-dependency using the β-adrenergic antagonist propranolol, although there was evidence of extinction. The results of these studies are discussed in terms of the strength of the memory trace and its subsequent susceptibility to amnestic treatments.