5-HT2a receptor in prefrontal cortex participates in the resolution of retroactive interference between object memories during consolidation

GALLO FRANCISCO; WEISSTAUB NOELIA V; MORICI JUAN FACUNDO; BEKINSCHTEIN PEDRO; MIRANDA MAGDALENA

Toronto

Congreso; 13th Annual Canadian Neuroscience Meeting; 2019

Historically, memory consolidation was associated with the activity of the medial temporal lobe. However, recently, it was shown that the Prefrontal cortex (PFC) also plays a role, particularly when interfering information is presented. The serotoninergic modulation of PFC has been linked with attentional and executive processes. Though, little is known about the role of this system during the consolidation of interfering memory traces. The object-in-context memory task (OIC) is a recognition protocol in which two object-context associations are generated. Then, dependingon the strength of the memory traces, interference between both memories could occurred. Since PFC serotonin type 2a receptor (5-HT2AR) activity has been shown to help prevent memory interference during retrieval, we wanted to evaluate if it participates in the control of memory interference during consolidation. We selectively modulated PFC 5-HT2AR activity after OIC-memory acquisition in rats. We observed that activation of 5-HT2AR was required for the resolution of the OIC task only after a weak training that could not be retrieved 24 hs later. Moreover, the PFC 5-HT2AR activity seemed to be required only when two memory consolidation processes were triggered within a specific time window. However, blockade of 5-HT2AR did not affect OIC-memory consolidation when animals generated a long-lasting memory. In summary, our results suggest that the PFC 5-HT2AR activity prevent memory interference in a time and strength dependent way.