Navegando por Palavras-chave "Urocortin 1"

Agora exibindo 1 - 2 de 2
  • Nenhuma Miniatura disponível
    Item
    Somente Metadadados
    CRF family peptides are differently altered by acute restraint stress and chronic unpredictable stress
    (Elsevier B.V., 2014-09-01) Andrade, José Simões de [UNIFESP]; Viana, Milena de Barros [UNIFESP]; Abrão, Renata Oliveira [UNIFESP]; Bittencourt, Jackson C.; Céspedes, Isabel Cristina [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Universidade de São Paulo (USP)
    Corticotropin-releasing factor (CRF) acts to promote stress-like physiological and behavioral responses and is mainly expressed in the paraventricular hypothalamic nucleus (PVN). Urocortin 1 (Ucn1) is also a ligand to CRF type 1 and 2 receptors that has been associated with the stress response. Ucnl neurons are primarily found in the Edinger-Westphal (EW) nucleus. It has been previously proposed that CRF and Ucnl differently modulate stress responses to distinct types of stressors. the present study used male Wistar rats to compare the effects of acute restraint stress and unpredictable chronic stress (UCS) through Fos-immunoreactivity (Fos-ir) on CRF-containing neurons of PVN and Ucn1-containing EW centrally projecting neurons. Results showed that PVN neurons responded to both acute restraint and UCS. Also for the PVN, unspecific variables, dependent on the time animals remained in the laboratory, do not seem to alter Fos-ir, since no significant differences between acute and chronic control groups were found. On the other hand, EW neurons were only activated in response to acute restraint stress. Also, for this nucleus a significant difference was found between acute and chronic control groups, suggesting that unspecific variables, dependent on the time animals remain in the laboratory, interfere with the nucleus activation. These results suggest that CRF/Ucn1 neuronal circuits encompass two interconnected systems, which are coordinated to respond to acute stressors, but are differentially activated during chronic unpredictable stress. (C) 2014 Elsevier B.V. All rights reserved.
  • Nenhuma Miniatura disponível
    Item
    Somente Metadadados
    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.