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

Dev Psychobiol. 2009 Dec;51(8):672-8. doi: 10.1002/dev.20402.


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.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Age Factors
  • Aging / physiology*
  • Analysis of Variance
  • Animals
  • Exploratory Behavior / physiology
  • Male
  • Pattern Recognition, Visual / physiology
  • Rats
  • Rats, Sprague-Dawley
  • Recognition, Psychology / physiology*
  • Time Factors