Base de dados : LILACS
Pesquisa : A08.186.211.132.659.413.875.595 [Categoria DeCS]
Referências encontradas : 54 [refinar]
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Id: lil-650579
Autor: Camplesi Jr, M.; Bortoli, V.C.de; Soares, V. de Paula; Nogueira, R.L.; Zangrossi Jr., H..
Título: Dorsal periaqueductal gray stimulation facilitates anxiety-, but not panic-related, defensive responses in rats tested in the elevated T-maze
Fonte: Braz. j. med. biol. res = Rev. bras. pesqui. méd. biol;45(11):1025-1030, Nov. 2012. ilus, tab.
Idioma: en.
Resumo: The escape response to electrical or chemical stimulation of the dorsal periaqueductal gray matter (DPAG) has been associated with panic attacks. In order to explore the validity of the DPAG stimulation model for the study of panic disorder, we determined if the aversive consequences of the electrical or chemical stimulation of this midbrain area can be detected subsequently in the elevated T-maze. This animal model, derived from the elevated plus-maze, permits the measurement in the same rat of a generalized anxiety- and a panic-related defensive response, i.e., inhibitory avoidance and escape, respectively. Facilitation of inhibitory avoidance, suggesting an anxiogenic effect, was detected in male Wistar rats (200-220 g) tested in the elevated T-maze 30 min after DPAG electrical stimulation (current generated by a sine-wave stimulator, frequency at 60 Hz) or after local microinjection of the GABA A receptor antagonist bicuculline (5 pmol). Previous electrical (5, 15, 30 min, or 24 h before testing) or chemical stimulation of this midbrain area did not affect escape performance in the elevated T-maze or locomotion in an open-field. No change in the two behavioral tasks measured by the elevated T-maze was observed after repetitive (3 trials) electrical stimulation of the DPAG. The results indicate that activation of the DPAG caused a short-lived, but selective, increase in defensive behaviors associated with generalized anxiety.
Descritores: Ansiedade/fisiopatologia
Comportamento Animal/efeitos dos fármacos
Reação de Fuga/efeitos dos fármacos
Transtorno de Pânico/fisiopatologia
Substância Cinzenta Periaquedutal/efeitos dos fármacos
-Comportamento Animal/fisiologia
Bicuculina/farmacologia
Eletrodos Implantados
Reação de Fuga/fisiologia
Aprendizagem em Labirinto/efeitos dos fármacos
Aprendizagem em Labirinto/fisiologia
Substância Cinzenta Periaquedutal/fisiologia
Ratos Wistar
Limites: Animais
Masculino
Ratos
Tipo de Publ: Research Support, Non-U.S. Gov't
Responsável: BR1.1 - BIREME


  2 / 54 LILACS  
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Id: lil-647755
Autor: Teodorov, E.; Ferrari, M.F.R.; Fior-Chadi, D.R.; Camarini, R.; Felício, L.F..
Título: Behavioral meaningful opioidergic stimulation activates kappa receptor gene expression
Fonte: Braz. j. med. biol. res = Rev. bras. pesqui. méd. biol;45(10):982-987, Oct. 2012. ilus, tab.
Idioma: en.
Resumo: The periaqueductal gray (PAG) has been reported to be a location for opioid regulation of pain and a potential site for behavioral selection in females. Opioid-mediated behavioral and physiological responses differ according to the activity of opioid receptor subtypes. The present study investigated the effects of the peripheral injection of the kappa-opioid receptor agonist U69593 into the dorsal subcutaneous region of animals on maternal behavior and on Oprk1 gene activity in the PAG of female rats. Female Wistar rats weighing 200-250 g at the beginning of the study were randomly divided into 2 groups for maternal behavior and gene expression experiments. On day 5, pups were removed at 7:00 am and placed in another home cage that was distant from their mother. Thirty minutes after removing the pups, the dams were treated with U69593 (0.15 mg/kg, sc) or 0.9% saline (up to 1 mL/kg) and after 30 min were evaluated in the maternal behavior test. Latencies in seconds for pup retrieval, grouping, crouching, and full maternal behavior were scored. The results showed that U69593 administration inhibited maternal behavior (P < 0.05) because a lower percentage of kappa group dams showed retrieval of first pup, retrieving all pups, grouping, crouching and displaying full maternal behavior compared to the saline group. Opioid gene expression was evaluated using real-time reverse-transcription polymerase chain reaction (RT-PCR). A single injection of U69593 increased Oprk1 PAG expression in both virgin (P < 0.05) and lactating female rats (P < 0.01), with no significant effect on Oprm1 or Oprd1 gene activity. Thus, the expression of kappa-opioid receptors in the PAG may be modulated by single opioid receptor stimulation and behavioral meaningful opioidergic transmission in the adult female might occur simultaneously to specific changes in gene expression of kappa-opioid receptor subtype. This is yet another alert for the complex role of the opioid ...
Descritores: Comportamento Animal/fisiologia
Lactação/fisiologia
Comportamento Materno/fisiologia
Substância Cinzenta Periaquedutal/efeitos dos fármacos
Receptores Opioides kappa/agonistas
-Comportamento Animal/efeitos dos fármacos
Expressão Gênica
Lactação/efeitos dos fármacos
Lactação/genética
Comportamento Materno/efeitos dos fármacos
Ratos Wistar
Reação em Cadeia da Polimerase Via Transcriptase Reversa
Receptores Opioides kappa/genética
Limites: Animais
Feminino
Ratos
Tipo de Publ: Research Support, Non-U.S. Gov't
Responsável: BR1.1 - BIREME


  3 / 54 LILACS  
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Id: lil-622758
Autor: Canteras, N.S.; Mota-Ortiz, S.R.; Motta, S.C..
Título: What ethologically based models have taught us about the neural systems underlying fear and anxiety
Fonte: Braz. j. med. biol. res = Rev. bras. pesqui. méd. biol;45(4):321-327, Apr. 2012. ilus.
Idioma: en.
Resumo: Classical Pavlovian fear conditioning to painful stimuli has provided the generally accepted view of a core system centered in the central amygdala to organize fear responses. Ethologically based models using other sources of threat likely to be expected in a natural environment, such as predators or aggressive dominant conspecifics, have challenged this concept of a unitary core circuit for fear processing. We discuss here what the ethologically based models have told us about the neural systems organizing fear responses. We explored the concept that parallel paths process different classes of threats, and that these different paths influence distinct regions in the periaqueductal gray - a critical element for the organization of all kinds of fear responses. Despite this parallel processing of different kinds of threats, we have discussed an interesting emerging view that common cortical-hippocampal-amygdalar paths seem to be engaged in fear conditioning to painful stimuli, to predators and, perhaps, to aggressive dominant conspecifics as well. Overall, the aim of this review is to bring into focus a more global and comprehensive view of the systems organizing fear responses.
Descritores: Tonsila do Cerebelo/fisiologia
Ansiedade/fisiopatologia
Condicionamento Psicológico/fisiologia
Medo/fisiologia
Substância Cinzenta Periaquedutal/fisiologia
-Ansiedade/psicologia
Modelos Animais de Doenças
Medo/psicologia
Modelos Neurológicos
Vias Neurais/fisiologia
Limites: Animais
Tipo de Publ: Research Support, Non-U.S. Gov't
Revisão
Responsável: BR1.1 - BIREME


  4 / 54 LILACS  
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Id: lil-622757
Autor: Fogaça, M.V.; Lisboa, S.F.; Aguiar, D.C.; Moreira, F.A.; Gomes, F.V.; Casarotto, P.C.; Guimarães, F.S..
Título: Fine-tuning of defensive behaviors in the dorsal periaqueductal gray by atypical neurotransmitters
Fonte: Braz. j. med. biol. res = Rev. bras. pesqui. méd. biol;45(4):357-365, Apr. 2012. tab.
Idioma: en.
Resumo: This paper presents an up-to-date review of the evidence indicating that atypical neurotransmitters such as nitric oxide (NO) and endocannabinoids (eCBs) play an important role in the regulation of aversive responses in the periaqueductal gray (PAG). Among the results supporting this role, several studies have shown that inhibitors of neuronal NO synthase or cannabinoid receptor type 1 (CB1) receptor agonists cause clear anxiolytic responses when injected into this region. The nitrergic and eCB systems can regulate the activity of classical neurotransmitters such as glutamate and γ-aminobutyric acid (GABA) that control PAG activity. We propose that they exert a ‘fine-tuning’ regulatory control of defensive responses in this area. This control, however, is probably complex, which may explain the usually bell-shaped dose-response curves observed with drugs that act on NO- or CB1-mediated neurotransmission. Even if the mechanisms responsible for this complex interaction are still poorly understood, they are beginning to be recognized. For example, activation of transient receptor potential vanilloid type-1 channel (TRPV1) receptors by anandamide seems to counteract the anxiolytic effects induced by CB1 receptor activation caused by this compound. Further studies, however, are needed to identify other mechanisms responsible for this fine-tuning effect.
Descritores: Ansiedade/fisiopatologia
Reação de Fuga/fisiologia
Neurotransmissores/fisiologia
Substância Cinzenta Periaquedutal/fisiologia
Transmissão Sináptica/fisiologia
-Ansiedade/metabolismo
Ácidos Araquidônicos/farmacologia
Agonistas de Receptores de Canabinoides/farmacologia
Endocanabinoides/farmacologia
Endocanabinoides/fisiologia
Óxido Nítrico/fisiologia
Substância Cinzenta Periaquedutal/metabolismo
Alcamidas Poli-Insaturadas/farmacologia
Canais de Cátion TRPV/fisiologia
Limites: Animais
Camundongos
Ratos
Tipo de Publ: Research Support, Non-U.S. Gov't
Revisão
Responsável: BR1.1 - BIREME


  5 / 54 LILACS  
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Id: lil-622756
Autor: Graeff, F.G..
Título: New perspective on the pathophysiology of panic: merging serotonin and opioids in the periaqueductal gray
Fonte: Braz. j. med. biol. res = Rev. bras. pesqui. méd. biol;45(4):366-375, Apr. 2012. ilus, tab.
Idioma: en.
Resumo: Panic disorder patients are vulnerable to recurrent panic attacks. Two neurochemical hypotheses have been proposed to explain this susceptibility. The first assumes that panic patients have deficient serotonergic inhibition of neurons localized in the dorsal periaqueductal gray matter of the midbrain that organize defensive reactions to cope with proximal threats and of sympathomotor control areas of the rostral ventrolateral medulla that generate most of the neurovegetative symptoms of the panic attack. The second suggests that endogenous opioids buffer normal subjects from the behavioral and physiological manifestations of the panic attack, and their deficit brings about heightened suffocation sensitivity and separation anxiety in panic patients, making them more vulnerable to panic attacks. Experimental results obtained in rats performing one-way escape in the elevated T-maze, an animal model of panic, indicate that the inhibitory action of serotonin on defense is connected with activation of endogenous opioids in the periaqueductal gray. This allows reconciliation of the serotonergic and opioidergic hypotheses of panic pathophysiology, the periaqueductal gray being the fulcrum of serotonin-opioid interaction.
Descritores: Peptídeos Opioides/fisiologia
Transtorno de Pânico/fisiopatologia
Substância Cinzenta Periaquedutal/fisiopatologia
Serotonina/fisiologia
-Substância Cinzenta Periaquedutal/metabolismo
Limites: Animais
Humanos
Ratos
Tipo de Publ: Research Support, Non-U.S. Gov't
Revisão
Responsável: BR1.1 - BIREME


  6 / 54 LILACS  
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Id: lil-622755
Autor: Miguel, T.T.; Gomes, K.S.; Nunes-de-Souza, R.L..
Título: Contrasting effects of nitric oxide and corticotropin- releasing factor within the dorsal periaqueductal gray on defensive behavior and nociception in mice
Fonte: Braz. j. med. biol. res = Rev. bras. pesqui. méd. biol;45(4):299-307, Apr. 2012. ilus.
Idioma: en.
Resumo: The anxiogenic and antinociceptive effects produced by glutamate N-methyl-D-aspartate receptor activation within the dorsal periaqueductal gray (dPAG) matter have been related to nitric oxide (NO) production, since injection of NO synthase (NOS) inhibitors reverses these effects. dPAG corticotropin-releasing factor receptor (CRFr) activation also induces anxiety-like behavior and antinociception, which, in turn, are selectively blocked by local infusion of the CRF type 1 receptor (CRFr1) antagonist, NBI 27914 [5-chloro-4-(N-(cyclopropyl)methyl-N-propylamino)-2-methyl-6-(2,4,6-trichlorophenyl)aminopyridine]. Here, we determined whether i) the blockade of the dPAG by CRFr1 attenuates the anxiogenic/antinociceptive effects induced by local infusion of the NO donor, NOC-9 [6-(2-hydroxy-1-methyl-2-nitrosohydrazino)-N-methyl-1-hexanamine], and ii) the anxiogenic/antinociceptive effects induced by intra-dPAG CRF are prevented by local infusion of Nω-propyl-L-arginine (NPLA), a neuronal NOS inhibitor, in mice. Male Swiss mice (12 weeks old, 25-35 g, N = 8-14/group) were stereotaxically implanted with a 7-mm cannula aimed at the dPAG. Intra-dPAG NOC-9 (75 nmol) produced defensive-like behavior (jumping and running) and antinociception (assessed by the formalin test). Both effects were reversed by prior local infusion of NBI 27914 (2 nmol). Conversely, intra-dPAG NPLA (0.4 nmol) did not modify the anxiogenic/antinociceptive effects of CRF (150 pmol). These results suggest that CRFr1 plays an important role in the defensive behavior and antinociception produced by NO within the dPAG. In contrast, the anxiogenic and antinociceptive effects produced by intra-dPAG CRF are not related to NO synthesis in this limbic midbrain structure.
Descritores: Comportamento Animal/efeitos dos fármacos
Nociceptividade/efeitos dos fármacos
Substância Cinzenta Periaquedutal/efeitos dos fármacos
Receptores de Hormônio Liberador da Corticotropina/antagonistas & inibidores
Triazenos/farmacologia
-Óxido Nítrico Sintase/farmacologia
Óxido Nítrico/farmacologia
Substância Cinzenta Periaquedutal/fisiologia
Receptores de Hormônio Liberador da Corticotropina/efeitos dos fármacos
Receptores de Hormônio Liberador da Corticotropina/fisiologia
Limites: Animais
Masculino
Camundongos
Tipo de Publ: Research Support, Non-U.S. Gov't
Responsável: BR1.1 - BIREME


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Id: lil-622750
Autor: Brenes, J.C.; Broiz, A.C.; Bassi, G.S.; Schwarting, R.K.W.; Brandão, M.L..
Título: Involvement of midbrain tectum neurokinin-mediated mechanisms in fear and anxiety
Fonte: Braz. j. med. biol. res = Rev. bras. pesqui. méd. biol;45(4):349-356, Apr. 2012. ilus.
Idioma: en.
Resumo: Electrical stimulation of midbrain tectum structures, particularly the dorsal periaqueductal gray (dPAG) and inferior colliculus (IC), produces defensive responses, such as freezing and escape behavior. Freezing also ensues after termination of dPAG stimulation (post-stimulation freezing). These defensive reaction responses are critically mediated by γ-aminobutyric acid and 5-hydroxytryptamine mechanisms in the midbrain tectum. Neurokinins (NKs) also play a role in the mediation of dPAG stimulation-evoked fear, but how NK receptors are involved in the global processing and expression of fear at the level of the midbrain tectum is yet unclear. The present study investigated the role of NK-1 receptors in unconditioned defensive behavior induced by electrical stimulation of the dPAG and IC of male Wistar rats. Spantide (100 pmol/0.2 μL), a selective NK-1 antagonist, injected into these midbrain structures had anti-aversive effects on defensive responses and distress ultrasonic vocalizations induced by stimulation of the dPAG but not of the IC. Moreover, intra-dPAG injections of spantide did not influence post-stimulation freezing or alter exploratory behavior in rats subjected to the elevated plus maze. These results suggest that NK-1 receptors are mainly involved in the mediation of defensive behavior organized in the dPAG. Dorsal periaqueductal gray-evoked post-stimulation freezing was not affected by intra-dPAG injections of spantide, suggesting that NK-1-mediated mechanisms are only involved in the output mechanisms of defensive behavior and not involved in the processing of ascending aversive information from the dPAG.
Descritores: Ansiedade/fisiopatologia
Reação de Fuga/fisiologia
Medo/fisiologia
Colículos Inferiores/efeitos dos fármacos
Neurocinina A/farmacologia
Substância Cinzenta Periaquedutal/efeitos dos fármacos
Receptores da Neurocinina-1/antagonistas & inibidores
Substância P/análogos & derivados
-Aprendizagem da Esquiva
Estimulação Elétrica
Colículos Inferiores/fisiologia
Substância Cinzenta Periaquedutal/fisiologia
Ratos Wistar
Substância P/farmacologia
Vocalização Animal
Limites: Animais
Masculino
Ratos
Tipo de Publ: Research Support, Non-U.S. Gov't
Responsável: BR1.1 - BIREME


  8 / 54 LILACS  
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Id: lil-617530
Autor: Ortiz, Blair; Herrera, Diego A; Vargas, Sergio.
Título: Aplicación clínica de las imágenes de resonancia magnética potenciadas en difusión y tractografía en un niño con holoprosencefalia / Clinical application of diffusion tensor imaging and tractography in a child with holoprosencephal
Fonte: Biomédica (Bogotá);31(2):164-167, jun. 2011. ilus.
Idioma: es.
Resumo: Las imágenes de resonancia magnética potenciadas en difusión y tractografía pueden emplearse en el estudio de las malformaciones congénitas del sistema nervioso central asociadas a anormalidades en los tractos de sustancia blanca. Presentamos un paciente con holoprosencefalia semilobar en quien la imagen potenciada en difusión y la tractografía demostró falla de la inducción ventral del prosencéfalo y fusión anormal de varios fascículos de la sustancia blanca en el cerebro y en el tallo encefálico. De esta forma, las anormalidades de los fascículos de la sustancia blanca en casos de holoprosencefalia se pueden identificar por medio de las imágenes potenciadas en difusión y tractografía fasciculografía.

Diffusion tensor imaging and fiber tracking can be methods used for the study of congenital brain malformations associated to white matter bundle abnormalities.Their use is illustrated in a child with semilobar holoprosencephaly in whom diffusion tensor imaging and tractography showed diencephalic ventral induction failure and abnormal white matter fascicles in brain and brainstem.
Descritores: Anisotropia
Imagem de Difusão por Ressonância Magnética
Insuficiência de Crescimento
Holoprosencefalia
Espectroscopia de Ressonância Magnética
Substância Cinzenta Periaquedutal
-Diagnóstico por Imagem
Responsável: CO42.1 - Biblioteca Nacional de Salud José Celestino Mutis


  9 / 54 LILACS  
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Id: lil-611095
Autor: Galvão, Bruno de Oliveira; Gomes, Vitor de Castro; Maisonnette, Silvia; Landeira- Fernandez, J.
Título: Panic-like behaviors in Carioca High-and Low-conditioned Freezing rats
Fonte: Psychol. neurosci. (Impr.);4(2):205-210, 2011. ilus.
Idioma: en.
Resumo: Panic disorder involves both recurrent unexpected panic attacks and persistent concern about having additional attacks. Electrical stimulation of the dorsal periaqueductal gray (dPAG) is an animal model of both panic attack and panic disorder, whereas contextual fear conditioning represents a model of anticipatory anxiety. Previous research indicated that anxiety has an inhibitory effect on panic attack-like behavior. However, still unclear is the role that anticipatory anxiety plays in panic disorder-like behaviors. This issue was investigated with two lines of animals selectively bred for high (Carioca High-Freezing) and low (Carioca Low-Freezing) freezing in response to contextual cues associated with footshock. The results suggest that although anticipatory anxiety might exert an inhibitory effect on the expression of panic attack, it might also facilitate the pathogenesis of panic disorder.
Descritores: Condicionamento Psicológico
Transtorno de Pânico
Comportamento de Esquiva
-Substância Cinzenta Periaquedutal
Limites: Animais
Ratos
Responsável: BR85.1 - Biblioteca Dante Moreira Leite


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Id: lil-611092
Autor: McNaughton, Neil.
Título: Fear, anxiety and their disorders: past, present and future neural theories
Fonte: Psychol. neurosci. (Impr.);4(2):173-181, 2011. ilus, tab.
Idioma: en.
Resumo: This paper reviews the historical development of a two-dimensional (direction x distance (?)) neural model of defense. It begins with Miller's (1944) analysis, and model, of approach, avoidance and conflict; adds Hinde's (1966) ethological perspective and Flynn's (1967) neural model of fear; and then considers Gray's (1967, 1970) work linking barbiturate action to the hippocampus, McNaughton's (1977) extension of this to other classes of anxiolytics, and Gray & McNaughton's (1983) detailed behavioral comparison of anxiolytics and hippocampal lesions. This work led to Gray's (1982) detailed model of the neuropsychology of anxiety. Rapoport's (1989) model of the control of obsession by the cingulate cortex, and Ledoux's (1994) model of the control of both fear and anxiety to the amygdala, suggested a more complex organisation of defense systems. McNaughton (1989) argued that evolutionary function defines an emotion, and Blanchard and Blanchard (1990) argued for its assessment via ethoexperimental analysis. Graeff (1994) then produced a neural model that mapped defensive distance to neural level, treating all anxiety as being at a greater defensive distance than fear. Seeing this, and the treatment of anxiety as due to uncertainty (which is inconsistent with Miller's data), as being unsatisfactory, Gray and McNaughton (2000) and then McNaughton and Corr (2004) developed the two-dimensional model of defensive systems. This model is clearly incomplete at the present time and its links with neuroeconomics, personality, and stress and greater specification of frontal cortical contributions are suggested as directions for future development.
Descritores: Medo
Transtornos de Ansiedade/história
-Tonsila do Cerebelo
Córtex Cerebral
Hipocampo
Hipotálamo
Substância Cinzenta Periaquedutal
Responsável: BR85.1 - Biblioteca Dante Moreira Leite



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