Do memories compete for proteins?

M. C. MARTÍNEZ; N. ALEN; F. BALLARINI; H. VIOLA

Huerta Grande, Cordoba

Congreso; IRCN, First joint meeting of the Argentine Society for Neurosciences (SAN) and the Argentine Workshop in Neurosciences (TAN); 2009

Argentine Society for Neurosciences (SAN)

The formation of long-term memories requires protein synthesis. We have demonstrated that learning of a task which only induces short-term memory can be stabilized into a long-term memory (LTM) if another novel experience brings in the necessary proteins. The phenomenon, named “behavioral tagging”, is observed when a weak inhibitory avoidance (IA) training induces a learning-tag which captures plasticity related proteins (PRPs) provided by the exploration of a novel open field (OF). Therefore, we decided to study the effects of this protein capture on the OF-LTM and found that induction of IA-LTM occurs in detriment of OF-LTM. This suggests that both IA and OF tags compete for protein sources and the availability of these plasticity factors determines which of the memory traces will become stable over time. In the present work we show that under certain circumstances memories can compete for their consolidation and it depends on PRPs supplies to the tagged sites. When PRPs amount is limited, competition is favored; but when PRPs synthesis is greater, there is an improvement in the promotion of the IA-LTM. Because of its role in synaptic remodeling, we also investigated the requirement of Arc/arg 3.1 as a PRP in the formation of LTM of both tasks as well as in the promotion of IA-LTM when its weak training is combined with novel OF exploration. We found Arc is necessary for the formation of both memories and it constitutes one of the PRPs captured by the tags previously set at IA-training. In sum, we show that depending on the amount of PRPs synthesis, different memory traces are able to “share” or compete for their resources, being Arc one of the proteins in dispute.