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

MORICI FACUNDO; GALLO FRANCISCO; MAGDALENA MIRANDA; BEKINSCHTEIN, PEDRO; NOELIA V WEISSTAUB

Mar del Plata

Congreso; XXX Reunion Anual de la Sociedad Argentina de Investigaciones en Neurociencias; 2015

Sociedad Argentina de Investigaciones en Neurociencias

Serotonin (5-HT) plays a role in the control of impulsive an other types of behavior.Increasing evidence shows that 5-HT is involved in learning and memory processes.However, role of 5-HT in recognition memory is poorly understood in particular inconditions that cause interference between memory traces. We have shown that blocking5-HT2AR or activating 5-HT1AR in the medial prefrontal cortex (mPFC) of rats impairs theresolution of an object in context task (OIC) in which the animal has to recognize a novelcombination of a familiar object and a familiar context. We postulated that both receptorsmight play a role in the resolution of OIC. If this is the case, then an imbalance of 5-HT2ARor 5-HT1AR signaling might alter the mnemonic function of mPFC. We tested thishypothesis using a genetically modified mice that present a global disruption of 5-HT2AR(htr2a-/-).We exposed htr2a -/- and htr2a+/+ to the OIC task. We found that htr2a -/- miceshowed a deficit in the resolution of the OIC task similar to the one observed in rats when5-HT2AR was blocked in mPFC during memory retrieval. Infusion of a selective 5-HT1ARantagonist in the mPFC before the retrieval session rescued the discrimination deficitobserved in htr2a-/- mice without affecting the performance in htr2a+/+ mice. These resultsuggest that 5-HT modulates mPFC function through 5-HT1AR and 5-HT2AR and that in theabsence of 5-HT2AR, 5-HT1A signaling affects the ability of the mPFC to control memoryinterference.