CONICET | Buscador de Institutos y Recursos Humanos

The specific characteristics of an experience will direct the recruitment of a structures that will participate in the formation of a new memory. Historically, memory consolidation was associated the activity of the medial temporal lobe. However, in recent years, it was shown that the Prefrontal cortex (PFC) also plays a role in memory consolidation, 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 serotoninergic modulation of PFC 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 during the training phase. Then, depending on the strength of the memory traces, interference between both memories could occurred Since serotonin modulation of PFC activity has been shown to help prevent memory interference during retrieval, we wanted to evaluate if it could participate in the control of memory interference during consolidation. We selectively modulated PFC serotonin type 2a receptor (5-HT2AR) activity after OIC-memory acquisition. We observed that activation of 5-HT2AR was required for the resolution of the OIC task only when the training protocol generated a weak OIC-memory trace that could not be retrieved 24 hs later. However, blockade of 5-HT2AR did not affect the OIC-memory consolidation when animals generated a long-lasting memory. Moreover, the 5-HT2AR modulation of PFC activity seemed to be required only when two memory consolidation processes were triggered within a specific time window. Our results suggest that serotonin modulation of PFC activity might help disambiguate competing memory traces in atime and strength dependent way.