The Serotoninergic system mediates interference resolution during memory retrieval phase in mice

MORICI JUAN FACUNDO; GALLO FRANCISCO; MIRANDA MAGDALENA; ZANONI BELEN; BEKINSCHTEIN PEDRO; WEISSTAUB NOELIA

Mar del Plata

Congreso; Congreso SAN 2015; 2015

Sociedad Argentina de Investigación en Neurociencias

Serotonin (5-HT) plays a role in the control of impulsive and other types of behavior. Increasing evidence shows that 5-HT is involved in learning and memory processes. However, the role of 5-HT in recognition memory is poorly understood, in particular in conditions that cause Interference between memory traces. We have shown that blocking 5-HT2AR or activating 5-HT1AR in the medial prefrontal cortex (mPFC) of rats impairs the resolution of an object in context task (OIC) in which the animal has to recognize a novel combination of a familiar object and a familiar context. We postulated that both receptors might play a role in the resolution of OIC. If this is the case, then an imbalance between 5-HT2AR and 5-HT1AR signaling might alter the mnemonic function of mPFC. We tested this hypothesis using a genetically modied mice that present a global disruption of 5-HT2AR (htr2a-/-). We exposed htr2a -/- and htr2a+/+ to the OIC task. We found that htr2a -/- mice showed a decit in the resolution of the OIC task similar to the one observed in rats when 5-HT2AR was blocked in mPFC during memory retrieval. Infusion of a selective 5-HT1AR antagonist in the mPFC before the retrieval session rescued the discrimination decit observed in htr2a-/- mice without aecting the performance in htr2a+/+ mice. These result suggests that 5-HT modulates mPFC function through 5-HT1AR and 5-HT2AR and that in the absence of 5-HT2AR, 5-HT1A signaling aects the ability of the mPFC to control memory interference.