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Role of cholinergic, opioidergic and GABAergic neurotransmission of the dorsal hippocampus in the modulation of nociception in guinea pigs

MENDES, Lys Angela Favaroni; MENESCAL-DE-OLIVEIRA, Leda
Fonte: PERGAMON-ELSEVIER SCIENCE LTD Publicador: PERGAMON-ELSEVIER SCIENCE LTD
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
37.19%
Aims: Several physiological, pharmacological and behavioral lines of evidence suggest that the hippocampal formation is involved in nociception. The hippocampus is also believed to play an important role in the affective and motivational components of pain perception. Thus, Our aim was to investigate the participation of cholinergic, opioidergic and GABAergic systems of the dorsal hippocampus (DH) in the modulation of nociception in guinea pigs. Main methods: The test used consisted of the application of a peripheral noxious stimulus (electric shock) that provokes the emission of a vocalization response by the animal. Key findings: Our results showed that, in guinea pigs, microinjection of carbachol, morphine and bicuculline into the DH Promoted anti nociception, while muscimol promoted pronociception. These results were verified by a decrease and all increase, respectively, in the vocalization index in the vocalization test. This antinociceptive effect of carbachol (2.7 nmol) was blocked by previous administration of atropine (0.7 nmol) or naloxone (1.3 nmol) into the same site. In addition, the decrease in the vocalization index induced by the microinjection of morphine (2.2 nmol) into the DH was prevented by pretreatment with naloxone (1.3 nmol) or muscimol (0.5 nmol). At doses of 1.0 nmol...

Involvement of the heme oxygenase-carbon monoxide-cGMP pathway in the nociception induced by acute painful stimulus in rats

CARVALHO, Priscila G.; BRANCO, Luiz G. S.; LEITE-PANISSI, Christie Ramos Andrade
Fonte: ELSEVIER SCIENCE BV Publicador: ELSEVIER SCIENCE BV
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.94%
Heme oxygenase-carbon monoxide-cGMP (HO-CO-cGMP) pathway has been reported to be involved in peripheral and spinal modulation of inflammatory pain. However, the involvement of this pathway in the modulation of acute painful stimulus in the absence of inflammation remains unknown. Thus, we evaluated the involvement of the HO-CO-cGMP pathway in nociception by means the of analgesia index (AI) in the tail flick test. Rats underwent surgery for implantation of unilateral guide cannula directed toward the lateral ventricle and after the recovery period (5-7 days) were subjected to the measures of baseline tail flick test Animals were divided into groups to assess the effect of intracerebroventricular administration (i.c.v.) of the following compounds: ZnDPBG (HO inhibitor) or vehicle (Na(2)CO(3)), heme-lysinate (substrate overload) or vehicle (L-lysine), or the selective inhibitor of soluble guanilate cyclase ODQ or vehicle (DMSO 1%) following the administration of heme-lysinate or vehicle. Heme overload increased AI, indicating an antinociceptive role of the pathway. This response was attenuated by i.c.v. pretreatment with the HO inhibitor ZnDPBG. In addition, this effect was dependent on cGMP activity, since the pretreatment with ODQ blocked the increase in the AI. Because CO produces most of its actions via cGMP...

Avaliação da influencia dos hormonios sexuais na nocicepção da articulação temporomandibular de ratos e estudo dos mecanismos envolvidos; The role of sex hormones in temporomandibular joint nociception and study of the mechanisms involved

Luana Fischer
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 18/02/2008 PT
Relevância na Pesquisa
27.51%
O objetivo deste estudo foi avaliar a influência dos hormônios sexuais na nocicepção da articulação temporomandibular (ATM) de ratos e os possíveis mecanismos envolvidos. A injeção de formalina na ATM em uma concentração (0,5%) que não induziu nocicepção em machos intactos, induziu em machos gonadectomizados e em fêmeas intactas, o que sugere que os níveis fisiológicos de testosterona diminuem o risco de machos desenvolverem nocicepção da ATM. A resposta nociceptiva induzida pela injeção de uma alta concentração de formalina (1,5%) na ATM de machos é significativamente menor que àquela induzida na ATM de fêmeas em diestro, fase do ciclo estral com baixos níveis de estrógeno, mas semelhante àquela induzida na ATM de fêmeas em proestro, faze do ciclo estral com altos níveis de estrógeno. Esse resultado sugere que a nocicepção da ATM, em fêmeas, é exacerbada durante a fase do ciclo estral em que os níveis de estrógeno estão baixos. A administração sistêmica de estrógeno ou progesterona em fêmeas gonadectomizadas e de testosterona em machos gonadectomizados reduz a resposta nociceptiva induzida pela injeção de formalina na ATM. A influência do sexo e dos hormônios ovarianos na nocicepção induzida pela injeção de formalina ou de glutamato na ATM foi exatamente a mesma...

Triagem farmacológica em cultura de células tumorais, em modelos de nocicepção e de ansiedade (Banisteriopsis caapi e Psychotria viridis); Pharmacological screening of ayahuasca in tumor cells culture, nociception and anxiety (Banisteriopsis caapi and Psychotria viridis)

Mariana Cecchetto Figueiredo
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 22/11/2013 PT
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37.09%
Este trabalho teve como objetivo realizar uma triagem inicial da ayahuasca em cultura de células e em modelos de nocicepção e ansiedade. A ayahuasca é uma decocção de duas plantas (Banisteriopsis caapi e Psychotria viridis) com ação alucinógena, utilizada por diversas religiões no Brasil. As principais substâncias relacionadas com as atividades no sistema nervoso central são a DMT(dimetiltriptamina), agonista serotoninérgico dos receptores 5HT1A, 2A/2C e as β-carbolinas, inibidoras da monoaminoxidase-A (MAO), encontradas na P. viridis e B. caapi, respectivamente. Nos últimos anos, a ayahuasca se espalhou pela Europa e Estados Unidos, chamando a atenção dos pesquisadores quanto aos seus efeitos. Desta forma, o presente trabalho revelou que a ayahuasca possui atividade sobre a nocicepção em modelos de contorção abdominal e placa quente, atividade ansiolítica em ratos submetidos aos testes de labirinto em cruz elevado (LCE) e efeito citostático leve em cultura de células tumorais humanas de mama (MCF-7), rim (786-0), pulmão (NCI-H460), próstata (PC-3), ovário (OVCAR-3), cólon (HT-29), mama resitente a múltiplas drogas (NCI-ADR).; This study aimed to perform an initial screening of ayahuasca in cultured cells and in models of nociception and anxiety. Ayahuasca is a decoction of two plants (Banisteriopsis caapi and Psyvhotria viridis) with hallucinogenic action...

Influence of arthritis on descending modulation of nociception from the paraventricular nucleus of the hypothalamus

Ribeiro, Filipa Pinto; Ansah, Osei B.; Almeida, Armando; Pertovaara, Antti
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em 04/03/2008 ENG
Relevância na Pesquisa
37.09%
We studied the influence of arthritis on descending modulation of nociception from the hypothalamic paraventricular nucleus (PVN) in the rat. Spinal nociception was assessed by the heat-evoked limb withdrawal in awake animals while neuronal responses were recorded in a potential brainstem relay, the rostroventromedial medulla (RVM), under pentobarbitone anesthesia. Following injection into the PVN, glutamate attenuated and lidocaine enhanced nociceptive spinal reflex responses in arthritic and control animals. In controls, PVN-induced antinociception was reversed by spinal administration of a 5-HT1A receptor or an α2-adrenoceptor antagonist but not by an opioid receptor antagonist. In arthritic animals, PVN-induced antinociception was not reversed by a 5-HT1A receptor antagonist, while the roles of α2-adrenoceptors or opioid receptors could not be assessed due to significant actions of antagonists alone. The spontaneous activity of presumably pronociceptive ON-cells of the RVM and that of antinociceptive OFF-cells was increased in arthritis. Lidocaine in the PVN increased ON-cell firing in control animals and decreased OFF-cell firing in arthritic animals, while glutamate failed to affect activity of RVM cells. The results indicate that the PVN influences phasic and tonic descending antinociception in arthritic as well as control conditions...

An electronic pressure-meter nociception paw test for rats

Vivancos,G.G.; Verri Jr.,W.A.; Cunha,T.M.; Schivo,I.R.S.; Parada,C.A.; Cunha,F.Q.; Ferreira,S.H.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2004 EN
Relevância na Pesquisa
36.94%
The objective of the present investigation was to compare the sensitivity of an electronic nociceptive mechanical paw test with classical mechanical tests to quantify the intensity variation of inflammatory nociception. The electronic pressure-meter test consists of inducing the hindpaw flexion reflex by poking the plantar region with a polypropylene pipette tip adapted to a hand-held force transducer. This method was compared with the classical von Frey filaments test and with the rat paw constant pressure test, a modification of the Randall and Selitto test developed by our group. When comparing the three methods, the electronic pressure-meter and the rat paw constant pressure test, but not the von Frey filaments test, detected time vs treatment interactions in prostaglandin E2 (PGE2)-induced hypernociception. Both methods also detected the PGE2-induced hypernociception in dose- (50-400 ng/paw) and time- (1-4 h) dependent manners, and time vs treatment interactions induced by carrageenin (25-400 µg/paw). Furthermore, the electronic pressure-meter test was more sensitive at early times, whereas the constant pressure test was more sensitive at later times. Moreover, the electronic pressure-meter test detected the dose-dependent antinociceptive effect of local indomethacin (30-300 µg/paw) and dipyrone (80-320 µg/paw) on carrageenin- (200 µg/paw) and PGE2- (100 ng/paw) induced hypernociception...

An electronic pressure-meter nociception paw test for mice

Cunha,T.M.; Verri Jr.,W.A.; Vivancos,G.G.; Moreira,I.F.; Reis,S.; Parada,C.A.; Cunha,F.Q.; Ferreira,S.H.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2004 EN
Relevância na Pesquisa
37.09%
The aim of the present investigation was to describe and validate an electronic mechanical test for quantification of the intensity of inflammatory nociception in mice. The electronic pressure-meter test consists of inducing the animal hindpaw flexion reflex by poking the plantar region with a polypropylene pipette tip adapted to a hand-held force transducer. This method was compared to the classical von Frey filaments test in which pressure intensity is automatically recorded after the nociceptive hindpaw flexion reflex. The electronic pressure-meter and the von Frey filaments were used to detect time versus treatment interactions of carrageenin-induced hypernociception. In two separate experiments, the electronic pressure-meter was more sensitive than the von Frey filaments for the detection of the increase in nociception (hypernociception) induced by small doses of carrageenin (30 µg). The electronic pressure-meter detected the antinociceptive effect of non-steroidal drugs in a dose-dependent manner. Indomethacin administered intraperitoneally (1.8-15 mg/kg) or intraplantarly (30-300 µg/paw) prevented the hypersensitive effect of carrageenin (100 µg/paw). The electronic pressure-meter also detected the hypernociceptive effect of prostaglandin E2 (PGE2; 10-100 ng) in a dose-dependent manner. The hypernociceptive effect of PGE2 (100 ng) was blocked by dipyrone (160 and 320 µg/paw) but not by intraplantar administration of indomethacin (300 µg/paw). The present results validate the use of the electronic pressure-meter as more sensitive than the von Frey filaments in mice. Furthermore...

Ocimum basilicum leaf essential oil and (-)-linalool reduce orofacial nociception in rodents: a behavioral and electrophysiological approach

Venâncio,Antônio M.; Marchioro,Murilo; Estavam,Charles S.; Melo,Mônica S.; Santana,Marília T.; Onofre,Alexandre S.C.; Guimarães,Adriana G.; Oliveira,Makson G. B.; Alves,Péricles B; Pimentel,Hugo de Carvalho; Quintans-Júnior,Lucindo J.
Fonte: Sociedade Brasileira de Farmacognosia Publicador: Sociedade Brasileira de Farmacognosia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2011 EN
Relevância na Pesquisa
37.09%
The present study investigated the antinociceptive effects of Ocimum basilicum L. (Lamiaceae) leaf essential oil (LEO) and (-)-linalool (LIN) in formalin (2%)-, glutamate (25 µM)- and capsaicin (2.5 µg)- induced orofacial nociception models in mice. The involvement of these substances was further evaluated on the neuronal excitability of the hippocampal dentate gyrus. Male mice (n=8/group) were pretreated separately with LEO and by LIN (50, 100, and 200 mg/kg, i.p.), morphine (5 mg/kg, i.p.) and vehicle (saline + Tween 80 0.2%), before injection of nociceptive agent into the right upper lip (perinasal area). The LEO and LIN reduced the nociceptive face-rubbing behaviour in both phases on formalin test. LEO and LIN, at high doses, produced significantly antinociceptive effect in the capsaicin and glutamate tests. In hippocampal slices, LEO inhibited the population spike generated by stimulation of the hylus (antidromic stimulation), with an IC50 of 0.1±0.05 mg/mL. This response was reversibly blocked by lidocaine (0.5 mg/mL), a known voltage-dependent sodium channel antagonist and by LIN (0.5 mg/mL). Our results suggest that LEO and LIN modulate neurogenic and inflammatory pain in the tests of orofacial nociception induced by formalin...

Contribution of vanilloid receptors to the overt nociception induced by B2 kinin receptor activation in mice

Ferreira, Juliano; da Silva, Gisele L; Calixto, João B
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
27.4%
The vanilloid receptor (TRPV1) is viewed as a molecular integrator of several nociceptive stimuli. In the present study, we have investigated the role played by TRPV1 in the nociceptive response induced by the peripheral activation of kinin B2 receptor in mice.The intraplantar (i.pl.) administration of bradykinin (BK) and the selective B2 agonist Tyr8-BK, or the vanilloid agonists resiniferatoxin and capsaicin, into the mouse paw induced a dose-related overt nociception of short duration. The B2 receptor antagonist Hoe 140 inhibited BK-induced, but not capsaicin-induced, nociceptive response. On the other hand, the TRPV1 antagonist capsazepine inhibited both capsaicin- and BK-mediated nociception.Repeated injections of BK or capsaicin produced desensitization to their nociceptive response. Capsaicin desensitization greatly reduced BK-induced nociception, but in contrast, the desensitization to BK increased the capsaicin response.Administration of low doses of capsaicin or acidified saline did not produce nociception when administered alone, but caused a pronounced effect when administered in association with a subthreshold dose of BK. Moreover, the degeneration of the subset of primary afferent fibers, sensitive to capsaicin, abolished both capsaicin- and BK-induced nociception.The inhibition of phospholipase C (PLC)...

The Effects of Cycling Levels of 17β-Estradiol and Progesterone on the Magnitude of Temporomandibular Joint-Induced Nociception

Kramer, P. R.; Bellinger, L. L.
Fonte: The Endocrine Society Publicador: The Endocrine Society
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
27.4%
A greater incidence of temporomandibular joint (TMJ) pain is reported in females, suggesting that gonadal hormones may play a role in this condition. However, the exact roles of 17β-estradiol (E2) and progesterone (P4) in TMJ pain are not completely known. Two experiments were performed to determine the separate roles of E2 and P4 in TMJ nociception at various stages of the estrous cycle. Ovariectomized (OVX) rats were cycled with physiological concentrations of E2 or P4. The E2-cycled rats then received bilateral TMJ injections of saline (SAL) or complete Freund’s adjuvant (CFA) on the morning of diestrus-2 (low E2 condition) or proestrus (high E2 condition). As a control, OVX rats (no ovarian E2 and no replacement) were injected with SAL or CFA. The TMJ nociception was measured using a validated novel method in which an increase in meal duration directly correlated to the intensity of deep TMJ nociception. In the E2 experiment, CFA injection, but not SAL, increased TMJ nociception in the OVX group, but the effect was less pronounced in diestrus-2 and even less in proestrus. In the P4 experiment, the rats receiving TMJ CFA in diestrus-2 (end of minor P4 surge) did not show an increase in TMJ nociception, whereas the rats injected in proestrus (major P4 surge)...

The Ankyrin Repeat Domain of the TRPA Protein Painless Is Important for Thermal Nociception but Not Mechanical Nociception

Hwang, Richard Y.; Stearns, Nancy A.; Tracey, W. Daniel
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 25/01/2012 EN
Relevância na Pesquisa
27.4%
The Drosophila TRPA channel Painless is required for the function of polymodal nociceptors which detect noxious heat and noxious mechanical stimuli. These functions of Painless are reminiscent of mammalian TRPA channels that have also been implicated in thermal and mechanical nociception. A popular hypothesis to explain the mechanosensory functions of certain TRP channels proposes that a string of ankyrin repeats at the amino termini of these channels acts as an intracellular spring that senses force. Here, we describe the identification of two previously unknown Painless protein isoforms which have fewer ankyrin repeats than the canonical Painless protein. We show that one of these Painless isoforms, that essentially lacks ankyrin repeats, is sufficient to rescue mechanical nociception phenotypes of painless mutant animals but does not rescue thermal nociception phenotypes. In contrast, canonical Painless, which contains Ankyrin repeats, is sufficient to largely rescue thermal nociception but is not capable of rescuing mechanical nociception. Thus, we propose that in the case of Painless, ankryin repeats are important for thermal nociception but not for mechanical nociception.

Modulation of nociception and pain by attention and stress

Cardinal-Aucoin, Natalie
Fonte: Université de Montréal Publicador: Université de Montréal
Tipo: Thèse ou Mémoire numérique / Electronic Thesis or Dissertation
EN
Relevância na Pesquisa
37.45%
Les facteurs psychologiques tels que l'hypnose, l'émotion, le stress et l’attention exercent un effet modulant puissant sur la nociception et la douleur. Toutefois, l’influence de l'attention sur la nociception et la douleur, ainsi que les mécanismes neuronaux sous-jacents, ne sont pas clairs. La littérature actuelle sur la modulation attentionnelle des réponses spinales nociceptives, telles que mesurées par le réflexe RIII, et de la perception de l’intensité de la douleur est discordante et souvent contradictoire. Ce mémoire fournit un nouveau cadre pour examiner la modulation du réflexe RIII et de la douleur par l’attention. Une tâche de discrimination sensorielle a été décomposée en trois composantes attentionnelles : la vigilance, l’orientation, et le contrôle exécutif. Auparavant, la nature multidimensionnelle de l’attention fut largement ignorée dans la littérature. Nous démontrons que les composantes attentionnelles ont des effets modulatoires distincts sur la nociception et la douleur et suggérons que ceci représente une partie de la confusion présente dans la littérature. En prenant compte du stress indépendamment, nous démontrons, pour la première fois, que le stress inhibe la modulation attentionnelle du réflexe RIII ce qui indique une interaction et dissociation de la modulation des réponses nociceptives par l’attention et le stress. Ces résultats importants clarifient...

Neuronal and Molecular Basis of Nociception and Thermosensation in Drosophila melanogaster

Zhong, Lixian
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Dissertação
Publicado em //2011
Relevância na Pesquisa
37.43%

From insects to mammals, the ability to constantly sense environmental stimuli is essential for the survival of most living organisms. Most animals have nocifensive behaviors towards extreme temperatures, mechanical stimuli or irritant chemicals that are considered to be noxious. Nociception is defined as the neural encoding and processing of noxious stimuli. This process starts from the activation of pain detecting peripheral sensory neurons (nociceptors) that can detect noxious mechanical, thermal or chemical stimuli. On the other hand, animals also have the ability to discriminate innocuous temperatures and to direct their locomotions to their favorable environmental temperatures and this behavior is called thermotaxis.

In this study, I used Drosophila melanogasteras a genetic model organism to study the molecular and cellular basis of nociception and thermotaxis. Drosophila larvae exhibit a stereotyped defensive behavior in response to nociceptive stimuli (termed nocifensive escape locomotion behavior, NEL). Using this behavior as a readout, we manipulated the neuronal activities of periphery sensory Type II multidendritic neurons and have identified a specific class of neurons, class IV multidendritic neurons...

Circuitry and Genes of Larval Nociception in Drosophila Melanogaster

Hwang, Richard Yi-Jen
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Dissertação Formato: 1925153 bytes; application/pdf
Publicado em //2009 EN_US
Relevância na Pesquisa
37.51%

Pain is defined by the international association of pain as an "unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage". Most people have experienced one form of pain or another and although such experiences can be unsavory, pain serves the basic need for the detection of dangerous stimuli that can cause bodily harm. Because pain serves such an essential need, it is important to understand how the nervous system processes and encodes noxious or potentially tissue damaging stimuli. This neural processing is called nociception.

In this study, I use Drosophila larvae as a genetic model organism to study nociception. In response to noxious thermal and mechanical stimuli, Drosophila larvae perform a nociceptive defensive behavior (termed nocifensive) where larvae rotate in a corkscrew like fashion along the long axis causing them to move in a lateral direction. Using this behavior and genetic tools which can manipulate neuronal output, we have identified the sensory neurons which serve as larval nociceptors as class IV multidendritic sensory neurons. Further characterization of these larval nociceptors, has also shown that they are both cholinergic and peptidergic.

After the identifying the larval nociceptors...

Genetic Analysis of the Contribution of Ion Channels to "Drosophila" Nociception

Walcott, Kia
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Dissertação
Publicado em //2012
Relevância na Pesquisa
37.47%

Nociceptors are specialized primary sensory neurons that represent the first line of defense against potentially tissue damaging environmental stimuli, and are involved in pathological pain states caused by nerve damage, inflammation and many chronic diseases. In nociception, these neurons detect harmful stimuli and contribute to the reactions to avoid them. Nociceptors transduce noxious stimuli into membrane depolarization, which in turn, triggers action potentials. These action potentials are conducted to synapses in the central nervous system (CNS), resulting in release of neurotransmitters at the presynaptic terminal. The unifying factor in the progression of nociceptive signaling i.e. transduction, action potential propagation, and neurotransmitter release, is the contribution of ion channels.

In this study, I use Drosophila melanogaster larvae as a model system to study the contribution of ion channels to nociception. Larvae stimulated with a noxious thermal or mechanical stimulus perform a stereotyped and quantifiable escape behavior. Larvae exhibiting this nocifensive behavior rotate around their long body axis in a corkscrew-like manner thus escaping the damage of the noxious stimulus. This behavior is triggered by the Class IV multidendritic (md) neurons...

Leptopilina Parasitoid Wasps, Ion Channels, and Dendritic Morphology in Drosophila Nociception Paradigms

Robertson, Jessica Leigh
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Dissertação
Publicado em //2013
Relevância na Pesquisa
27.4%

Almost everyone will experience pain at some point in their lives. While pain is generally adaptive, and alerts the body to potential tissue damage, chronic pain is a disruptive disease with a huge psychological and economic cost. Of all the senses, the molecular basis of pain is perhaps the least understood. Without an understanding of the genes involved in pain, it is difficult to develop new drugs to treat pain. Current pain drugs are often ineffective at treating pain, especially chronic pain, and can cause many side effects. In this dissertation, I have further developed the Drosophila nociception paradigm.

First, I investigated the responses of Drosophila melanogaster larvae to a naturally occurring noxious stimulus, the parasitoid wasp. These wasps use a sharp ovipositor to lay their eggs inside of the larvae. The eggs hatch, and the wasp larva then eats the Drosophila larva from the inside, resulting in the death of the Drosophila. In response, Drosophila larvae have evolved multiple mechanosensory behaviors to fight attacks from wasps. The type of defensive behavior depends on the somatotopic location of the attack along the larval body wall, as well as the degree of penetration of the larval cuticle by the wasp ovipositor. I found that the class IV neurons...

Degenerin/Epithelial Sodium Channels (DEG/ENaCs) Required for Mechanical Nociception Responses in Drosophila melanogaster

Mauthner, Stephanie
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Dissertação
Publicado em //2014
Relevância na Pesquisa
27.45%

Drosophila larvae respond to potentially tissue-damaging stimuli with nocifensive escape locomotion (NEL). NEL is a stereotyped withdrawal behavior in which the larva rotates along its long-body axis in a "corkscrew" pattern distinct from normal locomotion and is triggered by noxious heat (>39°C) or noxious mechanical (>30mN) stimuli. The Class IV multidendritic (md) neurons are the polymodal nociceptors responsible for triggering NEL. Recent evidence suggests that the pickpocket (ppk) gene, a degenerin/epithelial sodium channel (DEG/ENaC) subunit, is involved in the mechanotransduction of these neurons. While removal of this ion channel diminishes the larval response to noxious mechanical force, it does not completely abolish it, which leads us to hypothesize that additional mechanical nociception channels have yet to be identified. To identify these channels, we carried out a tissue specific RNAi screen and knocked down all known and predicted ion channels in the larval Class IV md nociceptors. Knockdown animals for each channel subunit were tested for behavioral responses to noxious mechanical force or noxious heat. Taking this approach, two novel channel genes were specifically required for mechanical responses - we named them stallone and balboa. Remarkably...

Systemic amantadine diminishes inflammatory and neuropathic nociception in the rat

Coffeen,Ulises; López-Ávila,Alberto; Pellicer,Francisco
Fonte: Instituto Mexicano de Psiquiatría Ramón de la Fuente Publicador: Instituto Mexicano de Psiquiatría Ramón de la Fuente
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/04/2009 EN
Relevância na Pesquisa
27.49%
The role of dopamine as a possible central inhibitory mediator of pain processes has been demonstrated. The administration of L-Dopa diminishes pain perception in humans as well as the response to nociceptive stimuli in animals. Also, the intracerebral microinjection of dopamine in inflammatory and neuropathic pain models (formalin test and deafferentation, respectively) reduces nociceptive response. In this sense, the selective activation of dopamine D2 receptors and the blockade of D1 in the insular cortex and spinal cord diminish nociception. Furthermore, the microinjection of dopamine or amantadine (dopamine releaser) in the anterior cingulate cortex (ACC) also reduces chronic nociception. The efficacy of amantadine has been tested in the treatment of neuropathic pain, even when given as a single dose. There is evidence of the role of amantadine as a releaser of dopamine (DA) calcium channel (N type) dependent in the striatum as well as a low affinity non-competitive antagonist of blockade/non-blockade kinetics of the NMDA receptor. This compound has also been described as a DA agonist and an inhibitor of its reuptake. With this background, we decided to test if the effects of systemically given amantadine related to acute nociception...

Endogenous opioids participation in the effect of Rosmarinus officinalis L. in the visceral, inflammatory and gout arthritis nociception in rodents

Martínez,Ana Laura; González-Trujano,Ma. Eva; López-Muñoz,Francisco J.
Fonte: Instituto Mexicano de Psiquiatría Ramón de la Fuente Publicador: Instituto Mexicano de Psiquiatría Ramón de la Fuente
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/04/2013 EN
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37.09%
The aim of this study was to investigate the endogenous opioid participation in the antinociceptive effect of R. officinalis aerial parts in experimental models of visceral, inflammatory and gout arthritis nociception. Acid-acetic induced writhing and formalin tests as well as the pain-induced functional impairment model in the rat (PIFIR) assay were studied. Antinociceptive doses of R. officinalis via oral, alone and in presence of an opioid antagonist were evaluated in comparison to the reference analgesic drug tramadol (31.6 and 50mg/kg i.p., in mice and rats, respectively). The antinociceptive effect of R. officinalis at a 300mg/kg dosage was significantly reverted in presence of 1.0mg/ kg s.c. of naloxone in writhing and formalin tests. Concerning PIFIR model, significant antinociceptive response produced for 1000 and 3000mg/kg was not inhibited in presence of 1.0 or 3.16mg/kg, s.c. of naloxone. In the antinociceptive effect of tramadol, naloxone produced partial inhibition in all models tested. These results suggest that antinociceptive and anti-inflammatory activities of R. officinalis aerial parts involve endogenous opioids, but activation of these mediators depends on the experimental model and the physiological process of the induced nociception.

Cardiovascular drugs in human mechanical nociception: digoxin, amlodipine, propranolol, pindolol and atenolol

Del Giaccio,Alfredo; Eblen-Zajjur,Antonio
Fonte: Universidad del Zulia Publicador: Universidad del Zulia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2010 EN
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Calcium channel blockers, β adrenergic receptor blockers and Na/K ATPase inhibitors are widely used drugs, mainly for cardiovascular diseases. Their pharmacological targets are not restricted to the cardivascular tissue, nociceptive system structures also express similar targets, which strongly suggests a direct effect on pain sensation. To evaluate the pain intensity changes in outpatient groups, who receive these drugs as a therapy, a cross-sectional sampled, randomized patient groups receiving the calcium channel blocker amlodipine for blood hypertension (n=45), β adrenergic receptor blockers (propranolol, atenolol or pindolol; n=40) for blood hypertension, or digoxin (n=40) for heart failure, were compared to an aparently healthy volunteers control group (n=60). A calibrated noxious pressure of 890 g/mm² was applied for 5 seconds on the patient’s sternum. Subjective pain intensity was reported by the visual analog scale (VAS, 0 to 10). Pain modulation system was evaluated by the application of a second stimulus with a 5 minutes delay. The analgesic effect of the β blockers group (propanolol, atenolol, pindolol) was dosage-dependant (-36.8%; P=0.0000003), without differences among them. The calcium channel blocker amlodipine showed lower pain scores (-50.6%; P=0.0000003) than β-receptor blockers (P=0.0000003). Digoxin presented the highest pain scores (+56.5%; P=0.0000003). All pain scores for the second stimulus were lower than the first stimulus and were differentially affected by β-blockers (atenolol...