Research reportConsolidation and reconsolidation of object recognition memory

- PRH and IC are necessary to consolidate object, but not object-in-context recognition memory.
- HIPP is necessary to consolidate object-in-context, but not object recognition memory.
- D1 dopamine receptors activity in the PRH but not in the HIPP is needed for ORM consolidation.
- Muscarinic receptor activity is required for LTM in the PRH but not in the HIPP.
- Retrieval is not necessary to reconsolidate ORM in the PRH.

In the first part of this review, we will present evidence showing a functional double dissociation between different structures of the medial temporal lobe in the consolidation of object and object-in-context recognition memory. In addition, we will provide evidence to support this differential participation through protein synthesis inhibitors and neurotransmitters antagonists and agonists. This evidence points out that the perirhinal, prefrontal and insular cortices consolidate the information of individual stimuli, i.e., objects, while the hippocampus consolidates the contextual information where the objects were experimented. In the second part of this review, we will present evidence that shows that the perirhinal cortex is also necessary for reconsolidation of ORM; the destabilization/re-stabilization memory process upon its activation. In the final part of this review, we will present evidence that shows that ORM reconsolidation is an independent process from its retrieval in the perirhinal cortex. Altogether, this review depicts part of the mechanisms by which the medial temporal lobe processes the functional components of recognition memory, in both consolidation and reconsolidation.