On the role of nociceptin/orphanin FQ hippocampal system in object recognition memory processing
Object recognition memory, Hippocampus, Nociceptin, NOP receptors.
Recognition memory refers to the ability to identify previously encountered events, objects, or individuals. It is one of the most crucial cognitive functions, enabling individuals to use past experiences to adapt to future situations. The hippocampus plays a central role in encoding new events and comparing them to stored experiences, allowing for necessary behavioral adjustments in response to changes. The novel object recognition (NOR) task is widely used to study object recognition memory (ORM) in rodents. Nociceptin/Orphanin FQ (N/OFQ) are highly expressed in the hippocampus, where they are known to regulate cognition. However, the involvement of hippocampal NOP receptors on different phases of ORM processing remains unclear. We found that intra-CA1 infusion of N/OFQ before, but not immediately after training in an ORM-inducing learning task dose-dependently impairs long-term ORM in adult male Wistar rats. Pre-test intrahippocampal N/OFQ infusion has no effect on retention. Taken together, our results suggest that N/OFQ disrupts ORM acquisition, but not consolidation or recall.