Navegando por Palavras-chave "periaqueductal gray matter"
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- ItemSomente MetadadadosANGIOTENSIN (5-8) MODULATES NOCICEPTION AT the RAT PERIAQUEDUCTAL GRAY VIA the NO-sGC PATHWAY and AN ENDOGENOUS OPIOID(Elsevier B.V., 2013-02-12) Guethe, L. M.; Pelegrini-da-Silva, A.; Borelli, K. G.; Juliano, M. A. [UNIFESP]; Pelosi, G. G.; Pesquero, J. B. [UNIFESP]; Silva, C. L. M.; Correa, F. M. A.; Murad, F.; Prado, W. A.; Martins, A. R.; Universidade de São Paulo (USP); Univ Fed Triangulo Mineiro; Universidade Federal de São Paulo (UNIFESP); Universidade Federal do Rio de Janeiro (UFRJ); George Washington Univ; Universidade Estadual de Londrina (UEL)Angiotensins (Angs) modulate blood pressure, hydro-electrolyte composition, and antinociception. Although Ang (5-8) has generally been considered to be inactive, we show here that Ang (5-8) was the smallest Ang to elicit dose-dependent responses and receptor-mediated antinociception in the rat ventrolateral periaqueductal gray matter (vlPAG). Ang (5-8) antinociception seems to be selective, because it did not alter blood pressure or act on vascular or intestinal smooth muscle cells. the non-selective Ang-receptor (Ang-R) antagonist saralasin blocked Ang (5-8) antinociception, but selective antagonists of Ang-R types I, II, IV, and Mas did not, suggesting that Ang (5-8) may act via an unknown receptor. Endopeptidase EP 24.11 and amastatin-sensitive aminopeptidase from the vlPAG catalyzed the synthesis (from Ang II or Ang III) and inactivation of Ang (5-8), respectively. Selective inhibitors of neuronal-nitric oxide (NO) synthase, soluble guanylyl cyclase (sGC) and a nonselective opioid receptor (opioid-R) inhibitor blocked Ang (5-8)-induced antinociception. in conclusion, Ang (5-8) is a new member of the Ang family that selectively and strongly modulates antinociception via NO-sGC and endogenous opioid in the vlPAG. (c) 2012 IBRO. Published by Elsevier B.V. All rights reserved.
- ItemAcesso aberto (Open Access)The brain decade in debate: II. Panic or anxiety? From animal models to a neurobiological basis(Associação Brasileira de Divulgação Científica, 2001-02-01) Andreatini, R.; Blanchard, C.; Blanchard, R.; Brandão, M.l.; Carobrez, A.p.; Griebel, G.; Guimarães, F.s.; Handley, S.l.; Jenck, F.; Leite, Jose Roberto [UNIFESP]; Rodgers, J.; Schenberg, L.c.; Da Cunha, C.; Graeff, F.g.; Universidade Federal do Paraná Departamento de Farmacologia Laboratório de Fisiologia e Farmacologia do Sistema Nervoso Central; University of Hawaii Department of Neurobiology; University of Hawaii Department of Psychology; Universidade de São Paulo (USP); Universidade Federal de Santa Catarina Departamento de Farmacologia; Central Nervous System Research Department Sanofi Synthelabo; Aston University Institute of Pharmaceutical Sciences; Hoffmann-La Roche Ltd.; Universidade Federal de São Paulo (UNIFESP); University of Leeds Department of Psychology Ethopharmacology Laboratory; Universidade Federal do Espírito Santo Centro de Biomedicina Departamento de Ciências FisiológicasThis article is a transcription of an electronic symposium sponsored by the Brazilian Society of Neuroscience and Behavior (SBNeC). Invited researchers from the European Union, North America and Brazil discussed two issues on anxiety, namely whether panic is a very intense anxiety or something else, and what aspects of clinical anxiety are reproduced by animal models. Concerning the first issue, most participants agreed that generalized anxiety and panic disorder are different on the basis of clinical manifestations, drug response and animal models. Also, underlying brain structures, neurotransmitter modulation and hormonal changes seem to involve important differences. It is also common knowledge that existing animal models generate different types of fear/anxiety. A challenge for future research is to establish a good correlation between animal models and nosological classification.
- ItemSomente MetadadadosON THE VERGE OF A RESPIRATORY-TYPE PANIC ATTACK: SELECTIVE ACTIVATIONS OF ROSTROLATERAL AND CAUDOVENTROLATERAL PERIAQUEDUCTAL GRAY MATTER FOLLOWING SHORT-LASTING ESCAPE TO A LOW DOSE OF POTASSIUM CYANIDE(Pergamon-Elsevier Science Ltd, 2017) Torres Muller, Claudia Janaina; Quintino-Dos-Santos, Jeyce Willig; Schimitel, Fagna Giacomin; Tufik, Sergio [UNIFESP]; Beijamini, Vanessa; Canteras, Newton Sabino; Schenberg, Luiz CarlosIntravenous injections of potassium cyanide (KCN) both elicit escape by its own and facilitate escape to electrical stimulation of the periaqueductal gray matter (PAG). Moreover, whereas the KCN-evoked escape is potentiated by CO2, it is suppressed by both lesions of PAG and clinically effective treatments with panicolytics. These and other data suggest that the PAG harbors a hypoxiasensitive alarm system the activation of which could both precipitate panic and render the subject hypersensitive to CO2. Although prior c-Fos immunohistochemistry studies reported widespread activations of PAG following KCN injections, the employment of repeated injections of high doses of KCN (> 60 mu g) in anesthetized rats compromised both the localization of KCN-responsive areas and their correlation with escape behavior. Accordingly, here we compared the brainstem activations of saline-injected controls (air/saline) with those produced by a single intravenous injection of 40-mu g KCN (air/KCN), a 2-min exposure to 13% CO2 (CO2/saline), or a combined stimulus (CO2/KCN). Behavioral effects of KCN microinjections into the PAG were assessed as well. Data showed that whereas the KCN microinjections were ineffective, KCN intravenous injections elicited escape in all tested rats. Moreover, whereas the CO2 alone was ineffective, it potentiated the KCNevoked escape. Compared to controls, the nucleus tractus solitarius was significantly activated in both CO2/saline and CO2/KCN groups. Additionally, whereas the laterodorsal tegmental nucleus was activated by all treatments, the rostrolateral and caudoventrolateral PAG were activated by air/KCN only. Data suggest that the latter structures are key components of a hypoxia-sensitive suffocation alarm which activation may trigger a panic attack. (C) 2017 IBRO. Published by Elsevier Ltd. All rights reserved.
- ItemSomente MetadadadosOrganization of electrically and chemically evoked defensive behaviors within the deeper collicular layers as compared to the periaqueductal gray matter of the rat(Elsevier B.V., 2005-01-01) Bittencourt, A. S.; Nakamura-Palacios, E. M.; Mauad, H.; Tufik, Sergio [UNIFESP]; Schenberg, L. C.; Univ Fed Espirito Santo; Universidade Federal de São Paulo (UNIFESP)Stimulation of the periaqueductal gray matter (PAG) and the deeper layers of superior colliculus (SC) produces both freezing (tense immobility) and flight (trotting, galloping and jumping) behaviors along With exophthalmus (fully opened bulging eyes) and, less often, micturition and defecation. the topography of these behaviors within the distinct layers of SC remains unclear. Therefore, this study compared the defensive repertoire of intermediate (ILSC) and deep (DLSC) layers of SC to those of dorsolateral periaqueductal gray matter (DLPAG) and lateral periaqueductal gray matter (LPAG) [Neuroscience 125 (2004) 71]. Electrical stimulation was carried out through intensity- (0-70 mu A) and frequency-varying (0-130 Hz) pulses. Chemical stimulation employed a slow microinfusion of N-methyl-D-aspartic acid (NMDA, 0-2.3 nmol, 0.5 nmol/min). Probability curves of intensity-, frequency- and NMDA-evoked behaviors, as well as the unbiased estimates of median stimuli, were obtained by threshold logistic analysis. Compared with the PAG, the most important differences were the lack of frequency-evoked jumping in both layers of SC and the lack of NMDA-evoked galloping in the ILSC. Moreover, although galloping and jumping were also elicited by NMDA stimulation of DLSC, effective doses were about three times higher than those of DLPAG, suggesting the spreading of the injectate to the latter structure. in contrast, exophthalmus, immobility and trotting were evoked throughout the tectum structures. However, whatever the response and kind of stimulus, the lowest thresholds were always found in the DLPAG and the highest ones in the ILSC. Besides, neither the appetitive, nor the offensive, muricide or male reproductive behaviors were produced by any kind of stimulus in the presence of appropriate targets. Accordingly, the present data suggest that the deeper layers of SC are most likely involved in the increased attentiveness (exophthalmus, immobility) or restlessness (trotting) behaviors that herald a full-blown flight reaction (galloping, jumping) mediated in the PAG. (c) 2005 Published by Elsevier Ltd on behalf of IBRO.