Serotoninergic system mediate the resolution of memory tasks that needs control of interference during retrieval phase

MORICI, JUAN FACUNDO; GALLO, FRANCISCO TOMÁS; MIRANDA, MAGDALENA; ZANONI, BELÉN; BEKINSCHTEIN, PEDRO; WEISSTAUB, NOELIA V

Mar del Plata

Congreso; XXX Congreso Anual de la Sociedad Argentina de Investigación en Neurociencias; 2015

Sociedad Argentina de Investigación en Neurociencias

Serotonin (5-HT) plays a role in the control of impulsive and other types ofbehavior. Increasing evidence shows that 5-HT is involved in learning andmemory processes. However, the role of 5-HT in recognition memory ispoorly understood, in particular in conditions that cause interference betweenmemory traces. We have shown that blocking 5-HT2AR or activating5-HT1AR in the medial prefrontal cortex (mPFC) of rats impairs the resolutionof an object in context task (OIC) in which the animal has to recognizea novel combination of a familiar object and a familiar context. Wepostulated that both receptors might play a role in the resolution of OIC. Ifthis is the case, then an imbalance between 5-HT2AR and 5-HT1AR signalingmight alter the mnemonic function of mPFC. We tested this hypothesisusing a genetically modied mice that present a global disruption of5-HT2AR (htr2a-/-). We exposed htr2a -/- and htr2a+/+ to the OIC task. Wefound that htr2a -/- mice showed a decit in the resolution of the OIC tasksimilar to the one observed in rats when 5-HT2AR was blocked in mPFCduring memory retrieval. Infusion of a selective 5-HT1AR antagonist in themPFC before the retrieval session rescued the discrimination decit observedin htr2a-/- mice without aecting the performance in htr2a+/+mice. These result suggests that 5-HT modulates mPFC function through5-HT1AR and 5-HT2AR and that in the absence of 5-HT2AR, 5-HT1A signalingaects the ability of the mPFC to control memory interference.