Independent Cellular Processes for Hippocampal Memory Consolidation and Reconsolidation

TLDR

New memories undergo time‑dependent consolidation, while recalled memories become labile and must undergo reconsolidation to stabilize. The study aims to show that consolidation and reconsolidation are distinct, dissociable processes by infusing antisense oligodeoxynucleotides into the rat hippocampus. The authors used hippocampal antisense oligodeoxynucleotide infusions in rats to probe the separate roles of consolidation and reconsolidation. Consolidation depends on BDNF but not Zif268, whereas reconsolidation requires Zif268 but not BDNF, confirming BDNF’s specific role in consolidation and clarifying Zif268’s function in plasticity.

Abstract

The idea that new memories undergo a time-dependent consolidation process after acquisition has received considerable experimental support. More controversial has been the demonstration that established memories, once recalled, become labile and sensitive to disruption, requiring "reconsolidation" to become permanent. By infusing antisense oligodeoxynucleotides into the hippocampus of rats, we show that consolidation and reconsolidation are doubly dissociable component processes of memory. Consolidation involves brain-derived neurotrophic factor (BDNF) but not the transcription factor Zif268, whereas reconsolidation recruits Zif268 but not BDNF. These findings confirm a requirement for BDNF specifically in memory consolidation and also resolve the role of Zif268 in brain plasticity, learning, and memory.