Dopaminergic and Noradrenergic systems in memory stabilization: a behavioral tagging approach

FULLIO, CAMILA L.; SCHROEDER, MATÍAS NICOLÁS; MONCADA, DIEGO

Congreso; XXXV Annual Meeting of the Argentinian Society for Neuroscience Research; 2020

It is proposed that theconsolidation and reconsolidation of memories are based on a behavioral taggingand capture process. That is, the setting of a tag at the appropriate neuralsubstrate during learning, or memory reactivation, ensures the stabilization ofthe trace upon the capture of newly synthesized proteins (PRPs). Also, dopamineand noradrenalinehave been considered neuromodulators in various processes,including memory. Here, we studied whether these neurotransmitters and theirmain sources (Ventral Tegmental Area -VTA- and Locus coeruleus -LC-), act onmemory by regulating the synthesis of PRPs on brain structures where they willbe stored.We show that coupling theactivation of the VTA to a training in the spatial object recognition task, orthe reactivation of its memory, ensures the stabilization of the memory trace, otherwiseimpaired by the administration of protein synthesis inhibitors during learningor reconsolidation. This process relies on the function of hippocampaldopaminergic receptors and subsequent protein synthesis. Similar findings arereported for the LC and the β-adrenergic receptors, along with further insightson these neurotransmitter systems functions.Insummary, our results suggest that the VTA and the LC act over the hippocampusvia the D1/D5-dopaminergic and the β-adrenergic receptors, thus regulating thesynthesis of the PRPs required for memory stabilization; revealing a way inwhich neuromodulator systems regulate lasting memories.