Behavioral tagging is a general mechanism of long-term memory formation

BALLARINI, FABRICIO; ALEN, NADIA; M. C. MARTÍNEZ; D. MONCADA; H. VIOLA

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

SAN TAN

Behavioral tagging is a general mechanism of long-term memory formationIt is currently proposed that memories are stored by stable changes in synaptic weight modifying the activity of specific neuronal circuits. Then, synapses activated by learning will require the supply of new plasticity-related proteins (PRPs) for the formation of long term memory (LTM). In consequence, there should be a mechanism limiting the action of PRPs to recently activated synapses. To address this biological problem, the synaptic tagging and capture hypothesis postulated that a transient local synaptic tag is set at those recently activated synapses where PRPs will be specifically captured. Using two different behavioral events, it was possible to separate tagging from PRP synthesis. We demonstrated by using one hippocampus-dependent learning task that, in rats subjected to weak training protocols that induce only short term memory, LTM is promoted and formed when training sessions took place in contingence with a novel experience occurring during a critical time windows around training. The process named “behavioral tagging” requires protein synthesis induced by novelty. Here, we decided to study whether this process can be observed using other hippocampus-dependent (spatial object recognition) and an hippocampus-independent (conditioned taste aversion) tasks. We found that behavioral tagging operates in different hippocampus- and cerebral cortex-dependent learning tasks with different behavioral features, suggesting that it represents a general mechanism in LTM formation. These findings show the first comprehensive set of evidences indicating the existence of a behavioral tagging process, sharing synaptic tag properties like transient lifetime, independence of protein synthesis and specificity of input.