Retrieval of retrained and reconsolidated memories are associated with a distinct neural network

BAVASSI, LUZ; FORCATO, CECILIA; FERNÁNDEZ, RODRIGO S.; DE PINO, GABRIELA; PEDREIRA, MARÍA E.; VILLARREAL, MIRTA F.

Scientific Reports

Nature

Año: 2019 vol. 9

Consolidated memories can persist from a single day to years, and persistence is improved by retrainingor retrieval-mediated plasticity. One retrieval-based way to strengthen memory is the reconsolidationprocess. Strengthening occurs simply by the presentation of specifc cues associated with the originallearning. This enhancement function has a fundamental role in the maintenance of memory relevancein animals everyday life. In the present study, we made a step forward in the identifcation of braincorrelates imprinted by the reconsolidation process studying the long-term neural consequences whenthe strengthened memory is stable again. To reach such a goal, we compared the retention of pairedassociate memories that went through retraining process or were labilizated-reconsolidated. Usingfunctional magnetic resonance imaging (fMRI), we studied the specifc areas activated during retrievaland analyzed the functional connectivity of the whole brain associated with the event-related design.We used Graph Theory tools to analyze the global features of the network. We show that reconsolidatedmemories imprint a more locally efcient network that is better at exchanging information, comparedwith memories that were retrained or untreated. For the frst time, we report a method to elucidate theneural footprints associated with a relevant function of memory reconsolidation.