Journal article
Extinction, reacquisition, and rapid forgetting of eyeblink conditioning in developing rats
Learning & memory (Cold Spring Harbor, N.Y.), Vol.21(12), pp.696-708
12/2014
DOI: 10.1101/lm.036103.114
PMCID: PMC4236410
PMID: 25403458
Abstract
Eyeblink conditioning is a well-established model for studying the developmental neurobiology of associative learning and memory. However, age differences in extinction and subsequent reacquisition have yet to be studied using this model. The present study examined extinction and reacquisition of eyeblink conditioning in developing rats. In Experiment 1, post-natal day (P) 17 and 24 rats were trained to a criterion of 80% conditioned responses (CRs) using stimulation of the middle cerebellar peduncle (MCP) as a conditioned stimulus (CS). Stimulation CS-alone extinction training commenced 24 h later, followed by reacquisition training after the fourth extinction session. Contrary to expected results, rats trained starting on P17 showed significantly fewer CRs to stimulation CS-alone presentations relative to P24s, including fewer CRs as early as the first block of extinction session 1. Furthermore, the P17 group was slower to reacquire following extinction. Experiment 2 was run to determine the extent to which the low CR percentage observed in P17s early in extinction reflected rapid forgetting versus rapid extinction. Twenty-four hours after reaching criterion, subjects were trained in a session split into 50 stimulation CS-unconditioned stimulus paired trials followed immediately by 50 stimulation CS-alone trials. With this "immediate" extinction protocol, CR percentages during the first block of stimulation CS-alone presentations were equivalent to terminal acquisition levels at both ages but extinction was more rapid in the P17 group. These findings indicate that forgetting is observed in P17 relative to P24 rats 24 h following acquisition. The forgetting in P17 rats has important implications for the neurobiological mechanisms of memory in the developing cerebellum.
Details
- Title: Subtitle
- Extinction, reacquisition, and rapid forgetting of eyeblink conditioning in developing rats
- Creators
- Kevin L Brown - Department of Psychology, University of Iowa, Iowa City, Iowa 52242, USA kevin-brown@uiowa.eduJohn H Freeman - Department of Psychology, University of Iowa, Iowa City, Iowa 52242, USA
- Resource Type
- Journal article
- Publication Details
- Learning & memory (Cold Spring Harbor, N.Y.), Vol.21(12), pp.696-708
- DOI
- 10.1101/lm.036103.114
- PMID
- 25403458
- PMCID
- PMC4236410
- NLM abbreviation
- Learn Mem
- ISSN
- 1072-0502
- eISSN
- 1549-5485
- Publisher
- United States
- Grant note
- NS038890 / NINDS NIH HHS R01 NS038890 / NINDS NIH HHS
- Language
- English
- Date published
- 12/2014
- Academic Unit
- Psychological and Brain Sciences; Iowa Neuroscience Institute
- Record Identifier
- 9984065752402771
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