The characteristics of memory consolidation, reconsolidation, and state dependency have received considerable attention for many years. Three experiments examined the effects of the NMDA antagonist MK-801 on these phenomena in adolescent rats using passive avoidance conditioning. Experiment 1 demonstrated that immediate post-training administration of MK-801 produced a consolidation impairment at postnatal day 37. Experiment 2 extended this result, showing that MK-801 administered immediately following memory reactivation disrupted reconsolidation. Experiment 3 employed a state dependent reconsolidation design, where saline or MK-801 was administered immediately following memory reactivation, and again 20 min prior to the retention test. Retention by the training/testing matched groups (saline/saline and MK-801/MK-801) was comparable and better than the mismatched groups (saline/MK-801 and MK-801/saline) providing evidence of state dependency. These results extend the consolidation/reconsolidation literature to adolescent animals and provide evidence that some deficits described as reconsolidation impairments may be more aptly considered state dependent retention deficits.
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