Navegando por Palavras-chave "Fear conditioning"

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    Flavones from Erythrina falcata are modulators of fear memory
    (Biomed Central Ltd, 2014-08-05) Oliveira, Daniela Rodrigues de [UNIFESP]; Zamberlam, Claudia Raquel [UNIFESP]; Gaiardo, Renan Barreta [UNIFESP]; Rego, Gizelda Maia; Cerutti, Janete Maria [UNIFESP]; Cavalheiro, Alberto J.; Cerutti, Suzete Maria [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA); Universidade de São Paulo (USP)
    Background: Flavonoids, which have been identified in a variety of plants, have been demonstrated to elicit beneficial effects on memory. Some studies have reported that flavonoids derived from Erythrina plants can provide such beneficial effects on memory. the aim of this study was to identify the flavonoids present in the stem bark crude extract of Erythrina falcata (CE) and to perform a bioactivity-guided study on conditioned fear memory.Methods: the secondary metabolites of CE were identified by high performance liquid chromatography combined with a diode array detector, electrospray ionization tandem mass spectrometry (HPLC-DAD-ESI/MSn) and nuclear magnetic resonance (NMR). the buthanolic fraction (BuF) was obtained by partitioning. Subfractions from BuF (BuF1 - BuF6) and fraction flavonoidic (FfA and FfB) were obtained by flash chromatography. the BuF3 and BuF4 fractions were used for the isolation of flavonoids, which was performed using HPLC-PAD. the isolated substances were quantified by HPLC-DAD and their structures were confirmed by nuclear magnetic resonance (NMR). the activities of CE and the subfractions were monitored using a one-trial, step-down inhibitory avoidance (IA) task to identify the effects of these substances on the acquisition and extinction of conditioned fear in rats.Results: Six subclasses of flavonoids were identified for the first time in CE. According to our behavioral data, CE, BuF, BuF3 and BuF4, the flavonoidic fractions, vitexin, isovitexin and 6-C-glycoside-diosmetin improved the acquisition of fear memory. Rats treated with BuF, BuF3 and BuF4 were particularly resistant to extinction. Nevertheless, rats treated with FfA and FfB, vitexin, isovitexin and 6-C-glycoside-diosmetin exhibited gradual reduction in conditioned fear response during the extinction retest session, which was measured at 48 to 480 h after conditioning.Conclusions: Our results demonstrate that vitexin, isovitexin and diosmetin-6-C-glucoside and flavonoidic fractions resulted in a significant retention of fear memory but did not prevent the extinction of fear memory. These results further substantiate that the treatment with pure flavonoids or flavanoid-rich fractions might represent potential therapeutic approaches for the treatment of neurocognitive disorders, improvement of memory acquisition and spontaneous recovery of fear.
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    Genetic evidence for chromosome 4 loci influencing learning and memory
    (Academic Press Inc Elsevier Science, 2016) Anselmi, Mayara; Correa, Fernanda Junkes; Santos, José Ronaldo dos; Silva, Anatildes Feitosa; Cunha, João Antônio Sousa; Leão, Anderson Henrique França Figueiredo [UNIFESP]; Campelo, Clarissa Loureiro Chagas [UNIFESP]; Ribeiro, Alessandra Mussi [UNIFESP]; Silva, Regina Helena [UNIFESP]; Izídio, Geison Souza; Universidade Federal de São Paulo (UNIFESP)
    The Lewis (LEW) and SHR (Spontaneously Hypertensive Rats) inbred rat strains differ in several anxiety/emotionality and learning/memory-related behaviors. We aimed to search quantitative trait locus (QTL) that influence these behaviors and confirm their effects in a congenic rat strain SLA16 (SHR.LEW.Anxrr16). LEW females and SHR males were intercrossed to produce F2 rats (96/sex), which were all tested in the plus-maze discriminative avoidance task (PMDAT), open-field (OF), object recognition (OR), spontaneous alternation (SA) and fear conditioning (FC). All animals were genotyped for microsatellite markers located on chromosome (Chr) 4. Behavioral and genotypic data were used to perform factor and QTL analyses. Also, to confirm the QTL effects, we tested male and female SLA16 rats and their isogenic control SHR in the same behavioral tests. A factor analysis of the F2 population revealed a correlation between anxiety/emotionality related behaviors and learning/memory in both sexes. QTL analysis revealed two significant QTL in males and three in females, on behavioral parameters in the PMDAT, OF and FC. Four QTL found herein were confirmed in SLA16 rats. The SLA16 strain displayed lower levels of anxiety/emotionality, higher locomotor activity and deficits in learning/memory in comparison with SHR strain. The Chr 4 contains genes influencing anxiety/emotionality and learning/memory behaviors and the SLA16 strain represents a valuable tool in the search for them. The use of the SLA16 strain as a genetic model for studying behavioral phenomena and their implications for psychiatric disorders are discussed. (C) 2016 Elsevier Inc. All rights reserved.
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    M1 muscarinic receptors are necessary for retrieval of remote context fear memory
    (Pergamon-Elsevier Science Ltd, 2017) Patricio, Rafael Rodisanski [UNIFESP]; Kramer Soares, Juliana Carlota [UNIFESP]; Menezes Oliveira, Maria Gabriela [UNIFESP]
    Several studies have investigated the transition of consolidation of recent memory to remote memory in aversively motivated tasks, such as contextual fear conditioning (CFC) and inhibitory avoidance (IA). However, the mechanisms that serve the retrieval of remote memories, has not yet been fully understood. Some evidences suggest that the central cholinergic system appears be involved in the modulation of these processes. Therefore, the present study aimed to investigate the effects of a pre-test administration of dicyclomine, a high-affinity M1 muscarinic receptor antagonist, on the retrieval of remote memories in fear conditioning and IA tasks. Male Wistar rats were trained, and after 1 or 28 days, the rats received dicyclomine (16 or 32 mg/lcg, intraperitoneally, i.p.) and were tested in CFC, tone fear conditioning (TFC) and IA tasks. At both time intervals, 32 mg/kg dicydomine induced impairment of CFC. In TFC task only the performance of the rats 28 days after training was impaired. The IA task was not affected in any of the studied intervals. These findings suggest a differential contribution of muscarinic receptors on recent and remote memories retrieval revealing a more generalized role in remote memory. (C) 2016 Elsevier Inc. All rights reserved.
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    Neuromodulatory property of standardized extract Ginkgo biloba L. (EGb 761) on memory: Behavioral and molecular evidence
    (Elsevier B.V., 2009-05-07) Oliveira, Daniela R. [UNIFESP]; Sanada, Priscila F. [UNIFESP]; Saragossa Filho, A. C. [UNIFESP]; Innocenti, L. R.; Oler, Gisele [UNIFESP]; Cerutti, Janete M. [UNIFESP]; Cerutti, Suzete M. [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Univ Sao Francisco
    Although it has been suggested that the standardized Ginkgo biloba leaf extract (Egb 761) may have a beneficial effect on memory, the cellular and molecular changes that underlie this process are not yet well defined. the present study evaluated the effects of acute (one dose) or subacute treatments (one daily dose/seven days) with EGb 761 (0.5 g kg(-1) and 1.0 g kg(-1)) on rats submitted to a conditioned emotional response (CER) in comparison with positive (4 mg kg(-1) Diazepam) and negative (12% Tween 80) control groups. To this end, eighty (n = 10/group) adult, male, Wistar rats (+/- 250-300 g) were used in an off-baseline CER procedure. We here observed that the rats submitted to an acute and subacute EGb 761 treatments had acquisition of fear conditioning. Additionally, we investigate if the expression of genes previously associated with classical conditioning (CREB-1 and GAP-43) and new candidate genes (GFAP) are modulated following EGb 761 acute treatment. CREB-1, GAP-43 and GFAP mRNA and protein expressions were evaluated using both quantitative PCR (qPCR) and immunohistochemical analysis, respectively. We here show, for the first time, that EGb 761 modulated GAP-43, CREB-1 and GFAP expression in the prefrontal cortex, amygdala and hippocampus. We observed an underexpression of GAP-43 in all structures evaluated and over-expression of GFAP in the amygdala and hippocampus following acute G. biloba treatment when compared to control group (Tween; p<0.01). GAP-43 expression was decreased in prefrontal cortex and hippocampus in the subacute treatment with EGb 761. Subacute treatment with EGb 761 lead to a decreased CREB-1 in mPFC (p<0.001) and increased in the hippocampus to 1.0 g kg(-1) G. biloba group (p<0.001). the results obtained from immunohistochemical analysis support our aforementioned findings and revealed that the changes in expression occurred within specific regions in the areas evaluated. All together, our findings not only provide new evidence for a role of EGb 761 on memory but also identify molecular changes that underlie the fear memory consolidation. (C) 2008 Elsevier B.V. All rights reserved.
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    Understanding posttraumatic stress disorder through fear conditioning, extinction and reconsolidation
    (Pergamon-Elsevier Science Ltd, 2016) Careaga, Mariella Bodemeier Loayza [UNIFESP]; Girardi, Carlos Eduardo Neves [UNIFESP]; Suchecki, Deborah [UNIFESP]
    Careaga MBL, Girardi CEN, Suchecki D. Understanding posttraumatic stress disorder through fear conditioning, extinction and reconsolidation. NEUROSCI BIOBEHAV REV - Posttraumatic stress disorder (PTSD) is a psychopathology characterized by exacerbation of fear response. A dysregulated fear response may be explained by dysfunctional learning and memory, a hypothesis that was proposed decades ago. A key component of PTSD is fear conditioning and the study of this phenomenon in laboratory has expanded the understanding of the underlying neurobiological changes in PTSD. Furthermore, traumatic memories are strongly present even years after the trauma and maintenance of this memory is usually related to behavioral and physiological maladaptive responses. Persistence of traumatic memory may be explained by a dysregulation of two memory processes: extinction and reconsolidation. The former may explain the over-expression of fear responses as an imbalance between traumatic and extinction memory. The latter, in turn, explains the maintenance of fear responses as a result of enhancing trauma-related memories. Thus, this review will discuss the importance of fear conditioning for the establishment of PTSD and how failure in extinction or abnormal reconsolidation may contribute to the maintenance of fear response overtime. (C) 2016 Elsevier Ltd. All rights reserved.