Emotion-Induced Amnesia in Rats: Working Memory-Specific Impairment, Corticosterone-Memory Correlation, and Fear Versus Arousal Effects on Memory

Document Type

Article

Publication Date

9-2003

Digital Object Identifier (DOI)

https://doi.org/10.1101/lm.62903

Abstract

We have shown previously that psychological stress (predator exposure) impairs spatial memory in rats. We have extended that finding here to show that predator stress selectively impaired recently acquired (hippocampal-dependent) spatial working memory without affecting long-term (hippocampal-independent) spatial reference memory. We also investigated why predator exposure impairs memory. Was spatial memory impaired because of the fear-provoking aspects of predator exposure or only because the cat was a novel and arousing stimulus? If the latter possibility was correct, then any novel and arousing stimulus, independent of its emotional valence (i.e., aversive or appetitive), would impair memory. We found that spatial working memory was not impaired when the male rats were exposed to a sexually receptive female rat, a stimulus that was novel and arousing to them, but not aversive. We also found that there was an equivalent increase in serum corticosterone levels in male rats exposed to either a cat or a female rat, but only the cat-exposed rats exhibited a significant correlation between corticosterone levels and impaired memory. Overall, this series of experiments demonstrates that (1) predator stress selectively impaired working (hippocampal-dependent), but not reference (hippocampal-independent), memory; (2) a fear-provoking stimulus, and not merely novelty and increased arousal, impaired spatial memory; and (3) increased corticosterone levels correlated withimpaired spatial working memory only under predator exposure, that is, fear-provoking conditions.

Was this content written or created while at USF?

Yes

Citation / Publisher Attribution

Learning & Memory, v. 10, issue 5, p. 326-336

Share

COinS