A BEHAVIORAL-TAGGING PERSPECTIVE OF SPACED LEARNING: Persistence of consolidated memories can be modified in response to retraining.

CORREA, J; H. VIOLA; BUDRIESI, P; TINTORELLI, R

Villa Carlos Paz

Congreso; Sociedad Argentina de Neurociencias; 2019

SAN

In the present study we assessed the effects of spaced learning on memory persistence, using a spatial object recognition (SOR) task in rats. We observed that a weak SOR (wSOR) training session induced short but not long-term memory (LTM); whereas a strong SOR (sSOR) training session promoted 24 h-LTM which did not last 7 days. When animals were exposed to a retraining protocol in which a sSOR session was followed by a wSOR retraining session 24 h later, we found that LTM did persist for 7 d. This effect was dependent on protein synthesis and ERKs1/2 activity in the dorsal hippocampus. However, LTM persistence was not observed when animals received a test session 24 h after sSOR training . Also, neither a wSOR retraining session nor a test session performed 7 d after the sSOR training were effective to promote memory persistence. Given that, we propose that memory retrieval at the time of relearning is a key factor in this process. We found that a wSOR retraining session did not labilize the LTM induced by sSOR, suggesting that a reconsolidation process was not involved in the persistence effect of retraining. Based on the "behavioral tagging" hypothesis, we postulate that it is necessary a second round of SOR-learning tag and the supplement of protein synthesis for memory to persist. Our results suggest that retrieval induces these proteins and a retraining session could retag the original SOR-learning tag in a more efficient way than a test session.