Ontogeny of Rat Recognition Memory measured by the novel object recognition task

Authors

  • Maxine L. Reger,

    Corresponding author
    1. Department of Neurosurgery, University of California, Los Angeles, CA 90095
    2. The UCLA Brain Injury Research Center, University of California, Los Angeles,CA 90095
    3. Department of Psychology, University of California, Los Angeles, CA 90095
    • Department of Neurosurgery, University of California, Los Angeles, CA 90095
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  • David A. Hovda,

    1. Department of Neurosurgery, University of California, Los Angeles, CA 90095
    2. The UCLA Brain Injury Research Center, University of California, Los Angeles,CA 90095
    3. Department of Medical and Molecular Pharmacology, University of California, Los Angeles, CA 90095
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  • Christopher C. Giza

    1. Department of Neurosurgery, University of California, Los Angeles, CA 90095
    2. The UCLA Brain Injury Research Center, University of California, Los Angeles,CA 90095
    3. Division of Pediatric Neurology, University of California, Los Angeles, CA 90095, 18-228A NPI, University of California, Los Angeles Medical Center, P.O. Box 957039, Los Angeles, CA 90095.
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Abstract

Detection of novelty is an essential component of recognition memory, which develops throughout cerebral maturation. To better understand the developmental aspects of this memory system, the novel object recognition task (NOR) was used with the immature rat and ontogenically profiled. It was hypothesized that object recognition would vary across development and be inferior to adult performance. The NOR design was made age-appropriate by downsizing the testing objects and arena. Weanling (P20–23), juvenile (P29–40), and adult (P50+) rats were tested after 0.25, 1, 24, and 48 hr delays. Weanlings exhibited novel object recognition at 0.25 and 1 hr, while older animals showed a preference for the novel object out to 24 hr. These findings are consistent with previous research performed in humans and monkeys, as well as to studies using the NOR after medial temporal lobe damage in adult rats. © 2009 Wiley Periodicals, Inc. Dev Psychobiol 51: 672–678, 2009

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