Context preexposure prevents forgetting of a contextual fear memory: implication for regional changes in brain activation patterns associated with recent and remote memory tests - PubMed (original) (raw)

Context preexposure prevents forgetting of a contextual fear memory: implication for regional changes in brain activation patterns associated with recent and remote memory tests

Joseph C Biedenkapp et al. Learn Mem. 2007.

Abstract

Contextual fear conditioning was maintained over a 15-day retention interval suggesting no forgetting of the conditioning experience. However, a more subtle generalization test revealed that, as the retention interval increased, rats showed enhanced generalized fear to an altered context. Preexposure to the training context prior to conditioning, however, prevented this enhanced generalized fear from developing. These results support the hypothesis that the memory representation of the context degrades as the memory ages and is responsible for enhanced generalization. The implications of these results for systems consolidation versus forgetting interpretations of regional changes in neural activation patterns that occur as memories age are discussed.

PubMed Disclaimer

Figures

Figure 1

Figure 1

A. Illustration of the two contexts used in the first experiment. Context A was the training context and Context B was the generalization test context. B. Mean percentage freezing as a function of retention interval. Rats displayed significantly more freezing to Context A than to Context B, but only when the retention interval was 1 day. Error bars represent SEM.

Figure 2

Figure 2

A. Illustration of the three contexts used in the second experiment. Context A was the training context and Context B was the generalization test context. Rats were either preexposed to Context A or Context X. B. The mean percentage freezing when the retention interval was 1 day. Regardless of preexposure condition, rats displayed significantly more freezing to Context A than to Context B. C. The mean percentage freezing when the retention interval was 15 days. Rats preexposed to Context A displayed significantly more freezing to Context A than to Context B, but rats preexposed to the control Context, X, displayed the same level of freezing in both context. Error bars represent SEM.

Comment in

Similar articles

Cited by

References

    1. Antoniadis EA, McDonald RJ. Amygdala, hippocampus, and discrimination fear conditioning to context. Behav. Brain Res. 2000;108:1–19. - PubMed
    1. Bontempi B, Laurent-Demir C, Destrade C, Jaffard R. Time dependent reorganization of brain circuitry underlying long-term memory storage. Nature. 1999;400:671–674. - PubMed
    1. Eysenck HJ. A theory of the incubation of anxiety/fear responses. Behav. Res. Ther. 1968;6:309–321. - PubMed
    1. Fanselow MS, Rudy JW. Convergence of Experimental and Developmental Approaches to Animal Learning and Memory Processes. In: Carew T, Menzel R, Shatz C, editors. Mechanistic Relationships between Development and Learning: Beyond Metaphor. Dahlem Workshop Report. John Wiley & Sons Ltd; Chichester: 1998. pp. 15–29.
    1. Fletcher PC, Henson RNA. Frontal lobes and human memory. Insights from functional neuroimaging. Brain. 2001;124:849–881. - PubMed

Publication types

MeSH terms

LinkOut - more resources