Navegando por Palavras-chave "Corticotropin-releasing factor"

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    Dorsomedial hypothalamus CRF type 1 receptors selectively modulate inhibitory avoidance responses in the elevated T-maze
    (Elsevier B.V., 2014-09-01) Silva, Mariana Santos Carvalho de Faria [UNIFESP]; Pereira, Bruno Aranha [UNIFESP]; Céspedes, Isabel Cristina [UNIFESP]; Nascimento, Juliana Olivetti Guzman [UNIFESP]; Bittencourt, Jackson C.; Viana, Milena de Barros [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Universidade de São Paulo (USP)
    Corticotropin-releasing factor (CRF) plays a critical role in the mediation of physiological and behavioral responses to stressors. in the present study, we investigated the role played by the CRF system within the dorsomedial hypothalamus (DMH) in the modulation of anxiety- and panic-related responses. Male Wistar rats were administered into the DMH with CRF (125 and 250 ng/0.2 mu l, experiment 1) or with the CRFR1 antagonist antalarmin (25 ng/0.2 mu l, experiment 2) and 10 min later tested in the elevated T-maze (ETM) for inhibitory avoidance and escape measurements. in clinical terms, these responses have been respectively related to generalized anxiety and panic disorder. To further verify if the anxiogenic effects of CRF were mediated by CRFR1 activation, we also investigated the effects of the combined treatment with CRF (250 ng/0.2 mu l) and antalarmin (25 ng/0.2 mu l) (experiment 3). All animals were tested in an open field, immediately after the ETM, for locomotor activity assessment. Results showed that 250 ng/0.2 mu l of CRF facilitated ETM avoidance, an anxiogenic response. Antalarmin significantly decreased avoidance latencies, an anxiolytic effect, and was able to counteract the anxiogenic effects of CRF. None of the compounds administered altered escape responses or locomotor activity measurements. These results suggest that CRF in the DMH exerts anxiogenic effects by activating type 1 receptors, which might be of relevance to the physiopathology of generalized anxiety disorder. (C) 2014 Elsevier B.V. All rights reserved.
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    The Edinger-Westphal nucleus II: Hypothalamic afferents in the rat
    (Elsevier B.V., 2013-12-01) Silva, Andre V. da; Torres, Kelly R.; Haemmerle, Carlos A.; Céspedes, Isabel Cristina [UNIFESP]; Bittencourt, Jackson C.; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP)
    Numerous functions have been attributed to the Edinger-Westphal nucleus (EW), including those related to feeding behavior, pain control, alcohol consumption and the stress response. the LW is thought to consist of two parts: one controls accommodation, choroidal blood flow and pupillary constriction, primarily comprising cholinergic cells and projecting to the ciliary ganglion; and the other would be involved in the non-ocular functions mentioned above, comprising peptide-producing neurons and projecting to the brainstem, spinal cord and prosencephalic regions. Despite the fact that the EW is well known, its connections have yet to be described in detail. the aim of this work was to produce a map of the hypothalamic sources of afferents to the EW in the rat. We injected the retrograde tracer Fluoro-Gold into the EW, and using biotinylated dextran amine, injected into afferent sources as the anterograde control. We found retrogradely labeled cells in the following regions: subfornical organ, paraventricular hypothalamic nucleus, arcuate nucleus, lateral hypothalamic area, zona incerta, posterior hypothalamic nucleus, medial vestibular nucleus and cerebellar interpositus nucleus. After injecting BDA into the paraventricular hypothalamic nucleus, lateral hypothalamic area and posterior hypothalamic nucleus, we found anterogradely labeled fibers in close apposition to and potential synaptic contact with urocortin 1-immunoreactive cells in the EW. On the basis of our findings, we can suggest that the connections between the EW and the hypothalamic nuclei are involved in controlling stress responses and feeding behavior. (C) 2013 Elsevier B.V. All rights reserved.