184 research outputs found

    Sustained release of BCNU for the treatment of intraocular malignancies in animal models

    Get PDF
    Sustained release, of 1,3-his(2)chloroethyl)-l-nitrosourea (BCNU) via an episcleral implante

    Evaluation of the application of not traumatic linking and learning techniques in two races of horses

    Get PDF
    Existe un conjunto de prácticas que permiten la familiarización del potrillo con el entorno, además de facilitar la detección y el diagnóstico de enfermedades, malformaciones y/o lesiones posparto (Gónzalez del Pino et al, 2009). Se conocen como Técnicas de Vinculación y Aprendizaje no Traumáticas (TVANT) y son realizadas mediante un contacto diario, tanto con el potrillo como con su madre, implicando una revisión habitual a cada individuo desde el día 7 al 14 desde el nacimiento. Nuestra experiencia en raza Criolla ha mostrado que las TVANT producen resultados satisfactorios (Abbiati et al, 2016). El objetivo de este trabajo fue comparar la duración del proceso para las razas Criolla y Silla Argentino en las maniobras de las TVANT.Facultad de Ciencias Veterinaria

    Severe stress switches CRF action in the nucleus accumbens from appetitive to aversive.

    Get PDF
    Stressors motivate an array of adaptive responses ranging from \u27fight or flight\u27 to an internal urgency signal facilitating long-term goals. However, traumatic or chronic uncontrollable stress promotes the onset of major depressive disorder, in which acute stressors lose their motivational properties and are perceived as insurmountable impediments. Consequently, stress-induced depression is a debilitating human condition characterized by an affective shift from engagement of the environment to withdrawal. An emerging neurobiological substrate of depression and associated pathology is the nucleus accumbens, a region with the capacity to mediate a diverse range of stress responses by interfacing limbic, cognitive and motor circuitry. Here we report that corticotropin-releasing factor (CRF), a neuropeptide released in response to acute stressors and other arousing environmental stimuli, acts in the nucleus accumbens of naive mice to increase dopamine release through coactivation of the receptors CRFR1 and CRFR2. Remarkably, severe-stress exposure completely abolished this effect without recovery for at least 90 days. This loss of CRF\u27s capacity to regulate dopamine release in the nucleus accumbens is accompanied by a switch in the reaction to CRF from appetitive to aversive, indicating a diametric change in the emotional response to acute stressors. Thus, the current findings offer a biological substrate for the switch in affect which is central to stress-induced depressive disorders

    Corticotropin Releasing Factor-Induced CREB Activation in Striatal Neurons Occurs via a Novel Gβγ Signaling Pathway

    Get PDF
    The peptide corticotropin-releasing factor (CRF) was initially identified as a critical component of the stress response. CRF exerts its cellular effects by binding to one of two cognate G-protein coupled receptors (GPCRs), CRF receptor 1 (CRFR1) or 2 (CRFR2). While these GPCRs were originally characterized as being coupled to Gαs, leading to downstream activation of adenylyl cyclase (AC) and subsequent increases in cAMP, it has since become clear that CRFRs couple to and activate numerous other downstream signaling cascades. In addition, CRF signaling influences the activity of many diverse brain regions, affecting a variety of behaviors. One of these regions is the striatum, including the nucleus accumbens (NAc). CRF exerts profound effects on striatal-dependent behaviors such as drug addiction, pair-bonding, and natural reward. Recent data indicate that at least some of these behaviors regulated by CRF are mediated through CRF activation of the transcription factor CREB. Thus, we aimed to elucidate the signaling pathway by which CRF activates CREB in striatal neurons. Here we describe a novel neuronal signaling pathway whereby CRF leads to a rapid Gβγ- and MEK-dependent increase in CREB phosphorylation. These data are the first descriptions of CRF leading to activation of a Gβγ-dependent signaling pathway in neurons, as well as the first description of Gβγ activation leading to downstream CREB phosphorylation in any cellular system. Additionally, these data provide additional insight into the mechanisms by which CRF can regulate neuronal function
    corecore