DSpace Repository :: Browsing by Subject "MEMORIA"

Browsing by Subject "MEMORIA"

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AMPA receptors: A key piece in the puzzle of memory retrieval.
(2021) Pereyra, Magdalena; Medina, Jorge Horacio
"Retrieval constitutes a highly regulated and dynamic phase in memory processing. Its rapid temporal scales require a coordinated molecular chain of events at the synaptic level that support transient memory trace reactivation. AMPA receptors (AMPAR) drive the majority of excitatory transmission in the brain and its dynamic features match the singular fast timescales of memory retrieval. Here we provide a review on AMPAR contribution to memory retrieval regarding its dynamic movements along the synaptic compartments, its changes in receptor number and subunit composition that take place in activity dependent processes associated with retrieval. We highlight on the differential regulations exerted by AMPAR subunits in plasticity processes and its impact on memory recall"
Análisis comparativo de pipelines de procesamiento y algoritmos de detección de ensambles neuronales para imágenes de calcio
(2021) Mandelbaum, Martín; Kropff, Emilio
"En los últimos años, las imágenes de calcio se han convertido en una valiosa herramienta para registrar actividad neuronal en diversas áreas del cerebro. La disponibilidad de microscopios de fluorescencia miniaturizados y de bajo costo permite un mayor acceso a investigaciones de neurociencias, entre las cuales se destaca el estudio de la formación y consolidación de memorias en el hipocampo. El gran caudal de células que pueden ser visualizadas con estas técnicas, y la posibilidad de realizar estudios con animales comportándose libremente permiten obtener información valiosa sobre diversas áreas de interés. Estos registros, sin embargo, deben ser acompañados por extensos procesos de corrección, procesamiento, y deconvolución de las señales para aportar información útil. En este proyecto se trabajó con registros de actividad en la región CA3 del hipocampo de un ratón (Mus musculus) sobre el cual se implementaron distintos pipelines de procesamiento de imágenes de calcio, los cuales fueron comparados según su robustez ante distintos niveles de ruido. También se evaluó la consistencia de algoritmos de detección de ensambles neuronales, conjuntos de neuronas que presentan coactivación y que se cree que forman la base del procesamiento neuronal de la información."
Declarative memory consolidation dynamics: new time windows and its implications for clinical application
(2020) Moyano, Malen D.; Bonilla, Matías; Blanco, Marcelo F.; Brusco, Luis Ignacio; Pedreira, María Eugenia; Kaczer, Laura; Forcato, Cecilia
"After encoding, memories go through a labile state followed by a stabilization process known as consolidation. Once consolidated they can enter a new labile state after the presentation of a reminder (cue) of the original memory, followed by a period of re-stabilization (reconsolidation). In both processes, once stabilization/re-stabilization is accomplished the memory cannot be modified. Currently there are studies that show a rapid stabilization after 30 min, while others studies show that stabilization occurs after 6h. However, there are no studies evaluating short and long delays simultaneously. Knowing that there are spontaneous waves of destabilization (without the re-exposure to keys linked to learning) on which the consolidation and memory persistence depend, here we investigate whether declarative memories in humans suffer spontaneous labilization/stabilization processes after learning or if they only pass through a single time window of lability."
Detección de complejos K y su rol en la consolidación de la memoria declarativa durante el sueño
(2021) Carosi, Julia; Vázquez Chenlo, Aylin Agatha; Forcato, Cecilia; Ramele, Rodrigo
"El presente proyecto final tiene los siguientes objetivos: -Estudiar el rol de los Complejos K en la consolidación de la memoria declarativa durante el sueño. -Desarrollar un algoritmo de detección automática de Complejos K durante la fase II del sueño."
Dopamine D1/D5 receptors in the restrosplenial cortex are necessary to consolidate object recognition memory
(2022-07-22) de Landeta, Ana Belén; Medina, Jorge Horacio; Katche, Cynthia
"The retrosplenial cortex (RSC) has been widely related to spatial and contextual memory. However, we recently demonstrated that the anterior part of the RSC (aRSC) is required for object recognition (OR) memory consolidation. In this study, we aimed to analyze the requirement of dopaminergic inputs into the aRSC for OR memory consolidation in male rats. We observed amnesia at 24-h long-term memory when we infused SCH23390, a D1/D5 dopamine receptors antagonist, into aRSC immediately after OR training session. However, the same infusion had no effect on OR short-term memory. Then, we analyzed whether the ventral tegmental area (VTA) is necessary for OR consolidation. VTA inactivation by intra-VTA administration of muscimol, a GABAA agonist, immediately after an OR training session induced amnesia when animals were tested at 24 h. Moreover, we observed that this VTA inactivation-induced amnesia was reversed by the simultaneous intra-aRSC delivery of SKF38393, a D1/D5 receptor agonist. Altogether, our results suggest that VTA dopaminergic inputs to aRSC play an important modulatory role in OR memory consolidation."
False memory formation during Covid-19 quarantine: age, sleep quality and emotional variables. Preliminary results
(2020) Bonilla, Matías; León, Candela S.; Urreta Benítez, Facundo A.; Lippmann-Mazzaglia, Natalia; Calvo, Camila; Garrido, Manuel; Forcato, Cecilia
"False memories are memories of events that did not happen or are altered in their content. It has been shown that not only small distortions can be introduced into old memories but also entire memories of events that never occurred can be implanted. Age is a crucial factor in the formation of false memories. Currently there is no consensus on which age range is more vulnerable. Since the COVID-19 pandemic, anxiety and depression values are increased and these factors also influence the formation of false memories.Thus, our aim was to study how age and mood factors, such as anxiety and depression, influence the formation of false memories."
Functional connectivity of anterior retrosplenial cortex in object recognition memory
(2021) de Landeta, Ana Belén; Pereyra, Magdalena; Miranda, Magdalena; Bekinschtein, Pedro; Medina, Jorge Horacio; Katche, Cynthia
"Recognition memory can rely on three components: “what”, “where” and “when”. Recently we demonstrated that the anterior retrosplenial cortex (aRSC), like the perirhinal cortex (PRH) and unlike the hippocampus (HP), is required for consolidation of the “what” component. Here, we aimed at studying which brain structures interact with the aRSC to process object recognition (OR) memory in rats. We studied the interaction of six brain structures that are connected to the aRSC during OR memory processing: PRH, medial prefrontal cortex (mPFC), anteromedial thalamic nuclei (AM), medial entorhinal cortex (MEC), anterior cingulate cortex (ACC) and the dorsal HP (dHP). We previously described the role of the PRH and dHP, so we first studied the participation of the mPFC, AM, MEC and ACC in OR memory consolidation by bilateral microinfusions of the GABAA receptor agonist muscimol. We observed an impairment in OR long-term memory (LTM) when inactivating the mPFC, the AM and the MEC, but not the ACC. Then, we studied the functional connections by unilateral inactivation of the aRSC and each one of the six structures in the same (ipsilateral) or the opposite (contralateral) hemisphere. Our results showed an amnesic LTM effect in rats with ipsilateral inactivations of aRSC-PRH, aRSC-mPFC, aRSC-AM, or aRSC-MEC. On the other hand, we observed memory impairment when aRSC-ACC were inactivated in opposite hemispheres, and no effect when the aRSC-dHP connection was inactivated. Thus, our ipsilateral inactivation findings reveal that the aRSC and, at least one brain region required in OR LTM processing are essential to consolidate OR memory. In conclusion, our results show that several cortico-cortical and cortico thalamic pathways are important for OR memory consolidation."
The impact of time, age and frequency of use on recognizing personal items of our closest ones: Forensic implications. Preliminary results
(2021) Bonilla, Matías; Vidal, Vanesa; León, Candela S.; Urreta Benítez, Facundo A.; Forcato, Cecilia
"Sometimes people have to recognize belongings of close ones that were found in places where, for example, genocides took place. This is done in order to pinpoint a missing person's last whereabouts and in some cases because the family asks to keep with their belongings. To do this, one part of the process is asking the relatives of the missing person to identify the items. However, in some cases (e.g. the missing people during the last Argentine military dictatorship) these procedures have been put in doubt by the legal system in order to prevent errors such as two or more families recognizing the same item as their own and thus to prevent nonsense re-exposure to traumatic memories. To the best of our knowledge, there is a lack of studies evaluating our performance on recognition of clothes from close ones. It is known that our capacity to correctly recognize items depends on various factors, such as age, frequency of item exposure, level of stress, sleep, among others [1-4]. Here, we will discuss preliminary data of how different factors such as time, age and frequency of use modulate the capacity to correctly and falsely recognize personal items of close ones. These results can enlighten and help the everyday practice of organizations such asthe “Argentine Team of Forensic Anthropology” (EAAF) to make decisions about the reliability of the clothing recognition by the victim’s relatives."
K-Complex detection algorithm in non-REM sleep
(2020) Vázquez Chenlo, Aylin; Carosi, Julia; Carbonari, Giulia; Forcato, Cecilia; Ramele, Rodrigo
"In order to evaluate the relation between KC and memory processes our main goal was to create a method with Machine Learning techniques to characterize and identify KCs."
Non-linear susceptibility to interferences in declarative memory formation
(2022-06-29) Moyano, Malen D.; Carbonari, Giulia; Bonilla, Matías; Pedreira, María Eugenia; Brusco, Luis Ignacio; Kaczer, Laura; Forcato, Cecilia
"After encoding, memories go through a labile state followed by a stabilization process known as consolidation. Once consolidated they can enter a new labile state after the presentation of a reminder of the original memory, followed by a period of re-stabilization (reconsolidation). During these periods of lability the memory traces can be modified. Currently, some studies show a rapid stabilization after 30 min, while others show that stabilization occurs after longer periods (e.g. > 6 h). Here we investigate the effect of an interference treatment on declarative memory consolidation, comparing distinct time intervals after acquisition. On day 1, participants learned a list of non- syllable pairs (List 1). 5 min, 30 min, 3 h or 8 h later, they received an interference list (List 2) that acted as an amnesic agent. On day 2 (48 h after training) participants had to recall List 1 first, followed by List 2. We found that the List 1 memory was susceptible to interference when List 2 was administered 5 min or 3 h after learning but not when it was administered 30 min or 8 h after. We propose the possibility that this rapid memory protection could be induced by a fast and transient neocortical integration. Our results open a discussion about the contribution of molecular and systemic aspects to memory consolidation."
Persistence of spatial memory induced by spaced training involves a behavioral-tagging process
(2022-08-10) Correa, Julieta; Tintorelli, Ramiro; Budriesi, Pablo; Viola, Haydeé
"Spaced training, which involves long inter-trial intervals, has positive effects on memories. One of the main attributes of long-term memories (LTM) is persistence. Here, to identify the process that promotes LTM persistence by spaced learning, we used the spatial object recognition (SOR) task in rats. The protocol consisted of a first strong training session that induced LTM formation (tested 1 day after training), but not LTM persistence (tested 7 or 14 days after training); and a second weak training session that promoted memory persistence when applied 1 day, but not 7 days, after the first training. We propose that the promotion of memory persistence is based on the Behavioral Tagging (BT) mechanism operating when the memory trace is retrieved. BT involves the setting of a tag induced by learning which gives rise to input selectivity, and the use of plasticity-related proteins (PRPs) to establish the mnemonic trace. We postulate that retraining will mainly retag the sites initially activated by the original learning, where the PRPs needed for memory expression and/or induced by retrieval would be used to maintain a persistent mnemonic trace. Our results suggest that the mechanism of memory expression, but not those of memory reinforcement or reconsolidation, is necessary to promote memory persistence after retraining. The molecular mechanisms involve ERKs1/2 activity to set the SOR learning tag, and the availability of GluA2-containing AMPA receptor. In conclusion, both the synthesis of PRPs and the setting of learning tags are key processes triggered by retraining that allow SOR memory persistence."
Slow wave detection algorithm in non-REM sleep
(2020) Carbonari, Giulia; Carosi, Julia; Vázquez Chenlo, Aylin; Moris, Eugenia; Forcato, Cecilia; Ramele, Rodrigo; Larrabide, Ignacio
"Online detection of slow waves."
"Somnus": diseño y desarrollo de un sistema modular para polisomnografía
(2022-03) Szewach, Mariana; Tassara, Francisco; Benedetti, Pedro; Szlain, Darío; Paschetta, Federico
"El presente proyecto final de carrera consta del diseño y desarrollo de un sistema para polisomnografía con una arquitectura versátil que puede ser adaptada para su uso en distintas líneas de investigación. La misma se basa en un esquema modular que permitirá, en un futuro, reemplazar, agregar o quitar bloques según se crea conveniente."
Thermal effects on the switching kinetics of silver/manganite memristive systems
(2014-10) Stoliar, Pablo; Sánchez, M. J.; Patterson, Germán; Fierens, Pablo Ignacio
"We investigate the switching kinetics of oxygen vacancy (Ov) diffusion in La(5/8-y)Pr(y) Ca(3/8)MnO(3)-Ag (LPCMO–Ag) memristive interfaces by performing experiments on the temperature dependence of the high resistance state under thermal cycling. Experimental results are well reproduced by numerical simulations based on thermally activated Ov diffusion processes and fundamental assumptions relying on a recent model proposed to explain bipolar resistive switching in manganite-based cells. The confident values obtained for activation energies and the diffusion coefficient associated to Ov dynamics constitute a validation test for both model predictions and Ov diffusion mechanisms in memristive interfaces."
Time‑dependent inhibition of Rac1 in the VTA enhances long‑term aversive memory : implications in active forgetting mechanisms
(Scientific Reports, 2023-08-19) Dalto, Juliana F.; Medina, Jorge H.
The fate of memories depends mainly on two opposing forces: the mechanisms required for the storage and maintenance of memory and the mechanisms underlying forgetting, being the latter much less understood. Here, we show the effect of inhibiting the small Rho GTPase Rac1 on the fate of inhibitory avoidance memory in male rats. The immediate post-training micro-infusion of the specific Rac1 inhibitor NSC23766 (150 ng/0.5 µl/ side) into the ventral tegmental area (VTA) enhanced long-term memory at 1, 7, and 14 days after a single training. Additionally, an opposed effect occurred when the inhibitor was infused at 12 h after training while no effect was observed immediately after testing animals at 1 day. Control experiments ruled out the possibility that post-training memory enhancement was due to facilitation of memory formation since no effect was found when animals were tested at 1 h after acquisition and no memory enhancement was observed after the formation of a weak memory. Immediate post-training micro-infusion of Rac1 inhibitor into the dorsal hippocampus, or the amygdala did not affect memory. Our findings support the idea of a Rac1-dependent time-specific active forgetting mechanism in the VTA controlling the strength of a long-term aversive memory.
Word learning and semantic integration: memory reactivation as a key mechanism for building the mental lexicon
(2020) Laurino, Julieta; Forcato, Cecilia; Pedreira, María Eugenia; Kaczer, Laura
"Analyze the contribution of memory reactivation to the enhancement and updating of words’ meaning. Our hypothesis is that reactivating a novel word´s meaning could be a key mechanism for its lexical integration and plasticity."

Browsing by Subject "MEMORIA"

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