Contextual fear memories formed in the absence of the dorsal hippocampus decay across time.

TitleContextual fear memories formed in the absence of the dorsal hippocampus decay across time.
Publication TypeJournal Article
Year of Publication2012
AuthorsZelikowsky, M, Bissiere S, Fanselow MS
JournalThe Journal of neuroscience : the official journal of the Society for Neuroscience
Volume32
Issue10
Pagination3393-7
Date Published2012 Mar 7
ISSN1529-2401
KeywordsAnimals, Fear, Hippocampus, Male, memory, Rats, Rats, Long-Evans, Time Factors
Abstract

Mammals suffering damage to the hippocampus display a dramatic loss of explicit, recently formed memories (retrograde amnesia). In contrast, deficits in the ability to form new memories following hippocampal damage (anterograde amnesia) can be overcome with sufficient training. By combining contextual fear conditioning with lesions of the dorsal hippocampus in rats, we discovered that while animals can form long-term contextual fear memories in the absence of the hippocampus, these memories decay with time, lacking the permanence that is a hallmark characteristic of normal fear memories. These findings indicate that while it is initially possible to acquire explicit memories when the hippocampus is compromised, these memories cannot transfer from a recent to remote state. This suggests that memories formed outside the hippocampus may nevertheless require the hippocampus to undergo systems consolidation, which has important clinical implications for the treatment of memory disorders.

DOI10.1002/hipo.20954
Alternate JournalJ. Neurosci.