Tags

Type your tag names separated by a space and hit enter

Relearning a context-shock association after forgetting is an NMDAr-independent process.
Physiol Behav. 2015 Sep 01; 148:29-35.PB

Abstract

Infantile amnesia (i.e., the rapid rate of forgetting in young animals) is at least partially due to a memory retrieval, rather than a storage, failure as studies have shown that these engrams can continue to influence later behavior. For example, prior conditioning affects the neural mechanisms underlying future learning. In adult animals, the initial learning of a context-shock association depends upon N-Methyl-D-Aspartate (NMDA) receptors, but this conditioning renders subsequent learning to a similar context NMDAr-independent. In the present study, we examined whether this transition from NMDAr-dependent to NMDAr-independent context conditioning occurs even after infantile amnesia. Experiment 1 demonstrated that infant (i.e., postnatal day 17) rats acquire a context-shock association when trained with multiple shocks, as assessed by context freezing one day later. However, they exhibit significant forgetting of this association 10days later. Experiments 2 and 3 showed that even when animals had forgotten the initial learning experience, future conditioning to the same context was NMDAr-independent. There was evidence of a transition to NMDAr-independent context fear learning in animals exposed only to the foot shock in infancy (Experiment 3) or only to the context in infancy (Experiment 3 but not Experiment 2). These latter results suggest that animals do not have to be exposed to the entire conditioning procedure at postnatal day 17 to show a transition to NMDAr-independent context learning. These experiments add to a growing body of evidence that forgotten infant memories can continue to affect later behavior by demonstrating that prior experience alters the mechanisms of future learning.

Authors+Show Affiliations

School of Psychology, The University of New South Wales, Sydney 2052, Australia. Electronic address: diana.chan@unsw.edu.au.School of Psychology, The University of New South Wales, Sydney 2052, Australia. Electronic address: k.baker@unsw.edu.au.School of Psychology, The University of New South Wales, Sydney 2052, Australia. Electronic address: r.richardson@unsw.edu.au.

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

25446198

Citation

Chan, Diana, et al. "Relearning a Context-shock Association After Forgetting Is an NMDAr-independent Process." Physiology & Behavior, vol. 148, 2015, pp. 29-35.
Chan D, Baker KD, Richardson R. Relearning a context-shock association after forgetting is an NMDAr-independent process. Physiol Behav. 2015;148:29-35.
Chan, D., Baker, K. D., & Richardson, R. (2015). Relearning a context-shock association after forgetting is an NMDAr-independent process. Physiology & Behavior, 148, 29-35. https://doi.org/10.1016/j.physbeh.2014.11.004
Chan D, Baker KD, Richardson R. Relearning a Context-shock Association After Forgetting Is an NMDAr-independent Process. Physiol Behav. 2015 Sep 1;148:29-35. PubMed PMID: 25446198.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Relearning a context-shock association after forgetting is an NMDAr-independent process. AU - Chan,Diana, AU - Baker,Kathryn D, AU - Richardson,Rick, Y1 - 2014/11/08/ PY - 2014/08/30/received PY - 2014/10/31/revised PY - 2014/11/03/accepted PY - 2014/12/3/entrez PY - 2014/12/3/pubmed PY - 2016/3/24/medline KW - Fear KW - Infantile amnesia KW - MK801 KW - NMDA receptor SP - 29 EP - 35 JF - Physiology & behavior JO - Physiol Behav VL - 148 N2 - Infantile amnesia (i.e., the rapid rate of forgetting in young animals) is at least partially due to a memory retrieval, rather than a storage, failure as studies have shown that these engrams can continue to influence later behavior. For example, prior conditioning affects the neural mechanisms underlying future learning. In adult animals, the initial learning of a context-shock association depends upon N-Methyl-D-Aspartate (NMDA) receptors, but this conditioning renders subsequent learning to a similar context NMDAr-independent. In the present study, we examined whether this transition from NMDAr-dependent to NMDAr-independent context conditioning occurs even after infantile amnesia. Experiment 1 demonstrated that infant (i.e., postnatal day 17) rats acquire a context-shock association when trained with multiple shocks, as assessed by context freezing one day later. However, they exhibit significant forgetting of this association 10days later. Experiments 2 and 3 showed that even when animals had forgotten the initial learning experience, future conditioning to the same context was NMDAr-independent. There was evidence of a transition to NMDAr-independent context fear learning in animals exposed only to the foot shock in infancy (Experiment 3) or only to the context in infancy (Experiment 3 but not Experiment 2). These latter results suggest that animals do not have to be exposed to the entire conditioning procedure at postnatal day 17 to show a transition to NMDAr-independent context learning. These experiments add to a growing body of evidence that forgotten infant memories can continue to affect later behavior by demonstrating that prior experience alters the mechanisms of future learning. SN - 1873-507X UR - https://www.unboundmedicine.com/medline/citation/25446198/Relearning_a_context_shock_association_after_forgetting_is_an_NMDAr_independent_process_ DB - PRIME DP - Unbound Medicine ER -