S-055 | Role of 5-HT2A Receptor in Memory Interference Control : Combining pharmacology with electrophysilogical recordings in behaving rats

Cognition, Behavior, and Memory
Author: Maria Victoria Oberholzer | Email: vic.ober@gmail.com

Maria Victoria Oberholzer^1°, Esteban Valverde^2°, Noelia Weisstaub^1°,  Camila Zold^2°

^1° Instituto de Neurociencia Cognitiva y Traslacional Fundación Favaloro (INECO-CONICET)
^2° INSTITUTO DE FISIOLOGIA Y BIOFISICA BERNARDO HOUSSAY (IFIBIO HOUSSAY)

Effective episodic memory recall requires distinguishing between similar experiences. In rodents, this can be studied using the Object-in-Context (OIC) task, where animals must differenciate between two competing memories by using contextual cues. The medial prefrontal cortex (mPFC) is key in selecting the correct memory, a process influenced by neurotransmitters such as serotonin (5-HT). Blocking 5-HT2A receptors in the mPFC disrupts memory interference control but does not affect attentional processing . The hippocampal (HIP) connection with the mPFC is believed to provide contextual information to the mPFC during recall. Theta oscillations in the HIP, linked to exploratory behavior and memory processes, modulate mPFC activity. Local field potential (LFP) recordings show increased theta power in the ventral HIP and mPFC during object exploration. Coherence between both structures increases particularly when the object is incongruent (IO) and it correlates with animals’ performance. To assess how 5-HT2A receptor blockade in the mPFC affects HIP-mPFC synchrony during episodic memory recall, Wistar rats were implanted with tetrodes and cannulas in the mPFC and electrodes in the HIP. Preliminary results show that while vehicle-infused rats perform well on the OIC task , 5-HT2A antagonist infusion impairs performance. Further analysis will explore the impact of blocking 5-HT2AR in the mPFC on theta band coherence and mPFC unit activity during object exploration.