Examinando por Autor "Radiske, Andressa"

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  • Publicación
    Acceso abierto
    Cross-frequency phase-amplitude coupling between hippocampal theta and gamma oscillations during recall destabilizes memory and renders it susceptible to reconsolidation disruption
    (2020-08-12) Radiske, Andressa; Gonzalez, Maria Carolina; Conde-Ocazionez, Sergio A.; Rossato, Janine I.; Köhler, Cristiano A.; Cammarota, Martín; Neuro Ciencias
    Avoidance memory reactivation at recall triggers theta-gamma hippocampal phase amplitude coupling (hPAC) only when it elicits hippocampus-dependent reconsolidation. However, it is not known whether there is a causal relationship between these phenomena. We found that in adult male Wistar rats, silencing the medial septum during recall did not affect avoidance memory expression or maintenance but abolished hPAC and the amnesia caused by the intrahippocampal administration of reconsolidation blockers, both of which were restored by concomitant theta burst stimulation of the fimbria–fornix pathway. Remarkably, artificial hPAC generated by fimbria–fornix stimulation during recall of a learned avoidance response naturally resistant to hippocampus-dependent reconsolidation made it susceptible to reactivation-dependent amnesia. Our results indicate that hPAC mediates the destabilization required for avoidance memory reconsolidation and suggest that the generation of artificial hPAC at recall overcomes the boundary conditions of this process.
  • Publicación
    Acceso abierto
    Optogenetic inactivation of the medial septum impairs long-term object recognition memory formation
    (2022-06-07) Gonzalez, Maria Carolina; Radiske, Andressa; Rossato, Janine I.; Conde‑Ocazionez, Sergio A.; Bevilaqua, Lia R. M.; Cammarota, Martín; Neurociencias
    Theta is one of the most prominent extracellular synchronous oscillations in the mammalian brain. Hippocampal theta relies on an intact medial septum (MS) and has been consistently recorded during the training phase of some learning paradigms, suggesting that it may be implicated in hippocampus-dependent long-term memory process‑ing. Object recognition memory (ORM) allows animals to identify familiar items and is essential for remembering facts and events. In rodents, long-term ORM formation requires a functional hippocampus but the involvement of the MS in this process remains controversial. We found that training adult male Wistar rats in a long-term ORM-inducing learn‑ing task involving exposure to two diferent, but behaviorally equivalent novel stimuli objects increased hippocampal theta power, and that suppressing theta via optogenetic MS inactivation caused amnesia. Importantly, the amne‑sia was specifc to the object the animals were exploring when the MS was inactivated. Taken together, our results indicate that the MS is necessary for long-term ORM formation and suggest that hippocampal theta activity is causally linked to this process.
  • Publicación
    Acceso abierto
    Reactivation-dependent amnesia for object recognition memory is contingent on hippocampal theta–gamma coupling during recall
    (2021-12-15) Gonzalez, Maria Carolina; Radiske, Andressa; Conde-Ocazionez, Sergio A.; Rossato, Janine I.; Bevilaqua, Lia R. M.; Cammarota, Martín; Neurociencias
    Hippocampal dopamine D1/D5 receptor-dependent destabilization is necessary for object recognition memory (ORM) updating through reconsolidation. Dopamine also regulates hippocampal theta and gamma oscillations, which are involved in novelty and memory processing. We found that, in adult male rats, ORM recall in the presence of a novel object, but not in the presence of a familiar one, triggers hippocampal theta-gamma coupling. Hippocampal theta-gamma coupling (hPAC) does not happen when ORM destabilization is prevented by blocking D1/D5 receptors, but artificial hPAC generation during recall in the presence of a familiar object enables the amnesic effect of reconsolidation inhibitors. Therefore, hPAC controls ORM destabilization, and its modulation could increase reconsolidation-based psychotherapy efficacy.