Contextual fear memories formed in the absence of the dorsal hippocampus decay across time.
|Title||Contextual fear memories formed in the absence of the dorsal hippocampus decay across time.|
|Publication Type||Journal Article|
|Year of Publication||2012|
|Authors||Zelikowsky, M, Bissiere S, Fanselow MS|
|Journal||The Journal of neuroscience : the official journal of the Society for Neuroscience|
|Date Published||2012 Mar 7|
|Keywords||Animals, Fear, Hippocampus, Male, memory, Rats, Rats, Long-Evans, Time Factors|
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.
|Alternate Journal||J. Neurosci.|