60 research outputs found

    Maintenance of aversive memories shown by fear extinction-impaired phenotypes is associated with increased activity in the amygdaloid-prefrontal circuit

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    Although aversive memory has been mainly addressed by analysing the changes occurring in average populations, the study of neuronal mechanisms of outliers allows understanding the involvement of individual differences in fear conditioning and extinction. We recently developed an innovative experimental model of individual differences in approach and avoidance behaviors, classifying the mice as Approaching, Balancing or Avoiding animals according to their responses to conflicting stimuli. The approach and avoidance behaviors appear to be the primary reactions to rewarding and threatening stimuli and may represent predictors of vulnerability (or resilience) to fear. We submitted the three mice phenotypes to Contextual Fear Conditioning. In comparison to Balancing animals, Approaching and Avoiding mice exhibited no middle- or long-term fear extinction. The two non-extinguishing phenotypes exhibited potentiated glutamatergic neurotransmission (spontaneous excitatory postsynaptic currents/spinogenesis) of pyramidal neurons of medial prefrontal cortex and basolateral amygdala. Basing on the a priori individuation of outliers, we demonstrated that the maintenance of aversive memories is linked to increased spinogenesis and excitatory signaling in the amygdala-prefrontal cortex fear matri

    Altered Functionality, Morphology, and Vesicular Glutamate Transporter Expression of Cortical Motor Neurons from a Presymptomatic Mouse Model of Amyotrophic Lateral Sclerosis

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    Amyotrophic lateral sclerosis (ALS) is a lethal disorder characterized by the gradual degeneration of motor neurons in the cerebrospinal axis. Whether upper motor neuron hyperexcitability, which is a feature of ALS, provokes dysfunction of glutamate metabolism and degeneration of lower motor neurons via an anterograde process is undetermined. To examine whether early changes in upper motor neuron activity occur in association with glutamatergic alterations, we performed whole-cell patch-clamp recordings to analyze excitatory properties of Layer V cortical motor neurons and excitatory postsynaptic currents (EPSCs) in presymptomatic G93A mice modeling familial ALS (fALS). We found that G93A Layer V pyramidal neurons exhibited altered EPSC frequency and rheobase values indicative of their hyperexcitability status. Biocytin loading of these hyperexcitable neurons revealed an expansion of their basal dendrite arborization. Moreover, we detected increased expression levels of the vesicular glutamate transporter 2 in cortical Layer V of G93A mice. Altogether our data show that functional and structural neuronal alterations associate with abnormal glutamatergic activity in motor cortex of presymptomatic G93A mice. These abnormalities, expected to enhance glutamate release and to favor its accumulation in the motor cortex, provide strong support for the view that upper motor neurons are involved early on in the pathogenesis of ALS

    Altered Functionality, Morphology, and Vesicular Glutamate Transporter Expression of Cortical Motor Neurons from a Presymptomatic Mouse Model of Amyotrophic Lateral Sclerosis.

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    Amyotrophic lateral sclerosis (ALS) is a lethal disorder characterized by the gradual degeneration of motor neurons in the cerebrospinal axis. Whether upper motor neuron hyperexcitability, which is a feature of ALS, provokes dysfunction of glutamate metabolism and degeneration of lower motor neurons via an anterograde process is undetermined. To examine whether early changes in upper motor neuron activity occur in association with glutamatergic alterations, we performed whole-cell patch-clamp recordings to analyze excitatory properties of Layer V cortical motor neurons and excitatory postsynaptic currents (EPSCs) in presymptomatic G93A mice modeling familial ALS (fALS). We found that G93A Layer V pyramidal neurons exhibited altered EPSC frequency and rheobase values indicative of their hyperexcitability status. Biocytin loading of these hyperexcitable neurons revealed an expansion of their basal dendrite arborization. Moreover, we detected increased expression levels of the vesicular glutamate transporter 2 in cortical Layer V of G93A mice. Altogether our data show that functional and structural neuronal alterations associate with abnormal glutamatergic activity in motor cortex of presymptomatic G93A mice. These abnormalities, expected to enhance glutamate release and to favor its accumulation in the motor cortex, provide strong support for the view that upper motor neurons are involved early on in the pathogenesis of ALS

    NGF-Dependent Changes in Ubiquitin Homeostasis Trigger Early Cholinergic Degeneration in Cellular and Animal AD-Model

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    Basal forebrain cholinergic neurons (BFCNs) depend on nerve growth factor (NGF) for their survival/differentiation and innervate cortical and hippocampal regions involved in memory/learning processes. Cholinergic hypofunction and/or degeneration early occurs at prodromal stages of Alzheimer’s disease (AD) neuropathology in correlation with synaptic damages, cognitive decline and behavioral disability. Alteration(s) in ubiquitin-proteasome system (UPS) is also a pivotal AD hallmark but whether it plays a causative, or only a secondary role, in early synaptic failure associated with disease onset remains unclear. We previously reported that impairment of NGF/TrkA signaling pathway in cholinergic-enriched septo-hippocampal primary neurons triggers “dying-back” degenerative processes which occur prior to cell death in concomitance with loss of specific vesicle trafficking proteins, including synapsin I, SNAP-25 and α-synuclein, and with deficit in presynaptic excitatory neurotransmission. Here, we show that in this in vitro neuronal model: (i) UPS stimulation early occurs following neurotrophin starvation (-1 h up to -6 h); (ii) NGF controls the steady-state levels of these three presynaptic proteins by acting on coordinate mechanism(s) of dynamic ubiquitin-C-terminal hydrolase 1 (UCHL-1)-dependent (mono)ubiquitin turnover and UPS-mediated protein degradation. Importantly, changes in miniature excitatory post-synaptic currents (mEPSCs) frequency detected in -6 h NGF-deprived primary neurons are strongly reverted by acute inhibition of UPS and UCHL-1, indicating that NGF tightly controls in vitro the presynaptic efficacy via ubiquitination-mediated pathway(s). Finally, changes in synaptic ubiquitin and selective reduction of presynaptic markers are also found in vivo in cholinergic nerve terminals from hippocampi of transgenic Tg2576 AD mice, even from presymptomatic stages of neuropathology (1-month-old). By demonstrating a crucial role of UPS in the dysregulation of NGF/TrkA signaling on properties of cholinergic synapses, these findings from two well-established cellular and animal AD models provide novel therapeutic targets to contrast early cognitive and synaptic dysfunction associated to selective degeneration of BFCNs occurring in incipient early/middle-stage of disease

    Athlete brand construction: A perspective based on fans’ perceptions

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    Abstract The purpose of this study was to develop a framework for understanding the antecedents and components of athlete brand. Based on a set of 21 interviews conducted in three different countries, a detailed framework is proposed including five antecedents and two components of athlete brand. The antecedents are media (social media, mass media, video games and major sport events), oral communications (word of mouth, and rumors and narratives), impression management, social agents (parents, family members, friends and community), and teams and sport (sport interest, team interest and team geographical location). In turn, the components of athlete brand are related with on-field attributes (behavior, team, achievements, style of play and skills) and off-field attributes (physical attraction, lifestyle, personal appeal, ethnicity and entertainment). Complementarily, these components of athlete brand are proposed to have an impact on fans' loyalty towards the athlete. Implications of these findings for building and managing athlete brand are discussed, and directions for future studies are provided

    Interleukin-10 contrasts inflammatory synaptopathy and central neurodegenerative damage in multiple sclerosis

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    Proinflammatory cytokines are implicated in promoting neurodegeneration in multiple sclerosis (MS) by affecting excitatory and inhibitory transmission at central synapses. Conversely, the synaptic effects of anti-inflammatory molecules remain underexplored, despite their potential neuroprotective properties and their presence in the cerebrospinal fluid (CSF) of patients. In a study involving 184 newly diagnosed relapsing–remitting (RR)-MS patients, we investigated whether CSF levels of the anti-inflammatory interleukin (IL)-10 were linked to disease severity and neurodegeneration measures. Additionally, we examined IL-10 impact on synaptic transmission in striatal medium spiny neurons and its role in counteracting inflammatory synaptopathy induced by IL-1β in female C57BL/6 mice with experimental autoimmune encephalomyelitis (EAE). Our findings revealed a significant positive correlation between IL-10 CSF levels and changes in EDSS (Expanded Disability Status Scale) scores one year after MS diagnosis. Moreover, IL-10 levels in the CSF were positively correlated with volumes of specific subcortical brain structures, such as the nucleus caudate. In both MS patients’ CSF and EAE mice striatum, IL-10 and IL-1β expressions were upregulated, suggesting possible antagonistic effects of these cytokines. Notably, IL-10 exhibited the ability to decrease glutamate transmission, increase GABA transmission in the striatum, and reverse IL-1β-induced abnormal synaptic transmission in EAE. In conclusion, our data suggest that IL-10 exerts direct neuroprotective effects in MS patients by modulating both excitatory and inhibitory transmission and attenuating IL-1β-induced inflammatory synaptopathy. These findings underscore the potential therapeutic significance of IL-10 in mitigating neurodegeneration in MS

    Controllo di gestione bancario: l'evoluzione digitale del controllo di MPS gestita da Techedge

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    La problematica dei controlli interni nelle banche, sia in Italia che all’estero, assume alla fine degli anni Novanta grande rilievo a motivo dell’accresciuta rischiosità dell’attività bancaria dovuta all’intensificarsi della competitività, dell’instabilità e dalla dinamicità dei mercati finanziari. In tale contesto i vertici bancari devono rafforzare l’efficacia degli strumenti di governo e di controllo aziendale. Il perseguimento della “sana e prudente gestione”, che è il principio di fondo al quale devono ispirarsi le banche, comporta che queste si dotino di adeguati sistemi di rilevazione, misurazione e controllo della rischiosità, e che tali sistemi siano costantemente monitorati, che le politiche aziendali siano definite e gestite coerentemente con il livello di rischiosità accettata e con gli obiettivi di tutela del patrimonio e di redditività definiti a livello strategico. Di fronte all’ampliarsi delle situazioni di instabilità le Autorità di controllo si sono rese conto della necessità di sollecitare le banche a condotte saldamente improntate alla “sana e prudente gestione” attraverso sia il potenziamento degli strumenti di controllo interno, che creano consapevolezza sui rischi assunti e sul loro andamento, sia il richiamo esplicito alla responsabilità del vertice aziendale (consiglio di amministrazione e alta direzione) nel governo di tali rischi. Il Comitato di Basilea, interpretando questa esigenza diffusa a livello internazionale, ha sollecitato le Autorità di vigilanza dei vari paesi a prendere in esame la necessità di definire in modo unitario, alla luce delle best practices, i criteri di valutazione della adeguatezza dei sistemi di controllo interno al fine di spingere al miglioramento di tali sistemi di controllo secondo uniformi modelli di riferimento. La focalizzazione dell’attenzione sulla rischiosità e sulle relazioni rischio/rendimento non solo consente di alimentare una cultura di controllo del rischio, ma opera anche nel senso della riduzione delle asimmetrie informative nel rapporto di agenzia e migliora l’efficacia del sistema di governance. Nel primo capitolo andremo ad analizzare, quindi, tutta la parte riconducibile al Sistema dei controlli Interni partendo dalla sua articolazione e soffermandoci per l’appunto su quei punti che caratterizzano tutto il sistema e le normative che lo disciplinano; inoltre faremo un focus su tutta la parte degli organi aziendali coinvolti in questo processo

    Impegno gastrointestinale e implicazioni sulla nutrizione nella sindrome di Sjögren

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    La sindrome di Sjögren è una condizione caratterizzata da una flogosi cronica ad eziologia autoimmune a carico di tessuti, in particolare sono colpite le ghiandole salivari e lacrimali, ma può interessare anche altri organi. I pazienti affetti da questa patologia spesso soffrono di una condizione nota come disfagia, ovvero la difficoltà a deglutire cibo solido e talvolta anche liquidi, che è dovuta alla ridotta/assente capacità della ghiandole salivari di produrre saliva. Questo rende necessario l'attuazione di comportamenti utili al fine di favorire la corretta progressione del cibo nell'esofago, come tagliare il cibo in pezzi molto piccoli, frullare gli alimenti, masticare a lungo e lentamente, bere molta acqua per la scarsa salivazione oppure usare molto olio in modo da lubrificare il cibo. Proprio grazie a questa forma di adattamento gli individui spesso presentano alterazioni a carico della composizione corporea che determinerà uno specifico fenotipo nutrizionale; infatti è possibile osservare all'interno di una coorte, pazienti sottopeso e contemporaneamente pazienti sovrappeso/obesi. Lo scopo del presente elaborato è quello di valutare, mediante appositi questionari, l'impegno gastrointestinale e le implicazioni sulla nutrizione nella sindrome di sjogren. Per rendere possibile lo svolgimento dello studio sono stati arruolati 57 pazienti a cui è stato proposto di compilare un questionario appositamente preparato. Il questionario è suddiviso in due macro parti: La prima parte è composta da un insieme di questionari che valutano l'andamento della sindrome, mentre la seconda parte mira a valutare l'impegno gastrointestinale. In conclusione, le risposte alle due parti dei questionari sono confrontate per valutare se c'è correlazione tra i seguenti segni e sintomi della malattia ed un coinvolgimento dell'apparato digerente e quindi sullo stato nutrizionale e la composizione corporea; che peraltro sono valutate, ai pazienti per cui si suppone un'alterazione, durante una visita presso l'ambulatorio di nutrizione dell'ospedale Santa Chiara di Pisa
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