Autor(es)

Santos, Thays Brenner ; Coelho, Cesar Augusto de Oliveira ; Kramer-Soares, Juliana Carlota ; Frankland, Paul W. ; Oliveira, Maria Gabriela Menezes

• Tipo de documento: Artigo Científico
• Fonte: NEUROPSYCHOPHARMACOLOGY; v. 49, n. 8, p. 13-pg., 2024-03-07.

Resumo

Fear conditioning is encoded by strengthening synaptic connections between the neurons activated by a conditioned stimulus (CS) and those activated by an unconditioned stimulus (US), forming a memory engram, which is reactivated during memory retrieval. In temporal associations, activity within the prelimbic cortex (PL) plays a role in sustaining a short-term, transient memory of the CS, which is associated with the US after a temporal gap. However, it is unknown whether the PL has only a temporary role, transiently representing the CS, or is part of the neuronal ensembles that support the retrieval, i.e., whether PL neurons support both transient, short-term memories and stable, long-term memories. We investigated neuronal ensembles underlying temporal associations using fear conditioning with a 5-s interval between the CS and US (CFC-5s). Controls were trained in contextual fear conditioning (CFC), in which the CS-US overlaps. We used Robust Activity Marking (RAM) to selectively manipulate PL neurons activated by CFC-5s learning and Targeted Recombination in Active Populations (TRAP2) mice to label neurons activated by CFC-5s learning and reactivated by memory retrieval in the amygdala, medial prefrontal cortex, hippocampus, perirhinal cortices (PER) and subiculum. We also computed their co-reactivation to generate correlation-based networks. The optogenetic reactivation or silencing of PL encoding ensembles either promoted or impaired the retrieval of CFC-5s but not CFC. CFC-5s retrieval reactivated encoding ensembles in the PL, PER, and basolateral amygdala. The engram network of CFC-5s had higher amygdala and PER centralities and interconnectivity. The same PL neurons support learning and stable associative memories. (AU)

• Processo FAPESP: 19/04844-5 - Identificação de pequenos grupos neurais seletivamente ativados (neuronal ensembles) no condicionamento de medo com componentes temporais e contextuais
• Beneficiário: Thays Brenner dos Santos
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Doutorado
• Processo FAPESP: 16/13027-2 - Rede neural subjacente à aquisição do condicionamento de medo em descontinuidade temporal e espacial: interações do córtex pré-límbico
• Beneficiário: Thays Brenner dos Santos
• Modalidade de apoio: Bolsas no Brasil - Doutorado