RESUMEN
Objetivou-se avaliar a influência da insensibilização inadequada durante o abate de suínos na cor, pH e perdas de água da carne. Após eletrocussão dos animais em um abatedouro-frigorífico sob SIF da região da Zona da Mata, Minas Gerais, parâmetros de insensibilização foram avaliados em 3.347 suínos abatidos. Os parâmetros avaliados foram ausência de reflexos palpebrais, reflexo de orelhas, gritos, pedalagem nos membros anteriores e respiração arrítmica. Após o completo abate e 16 horas de estocagem das carcaças em câmara fria a 2°C, fragmentos transversais do músculo Longissimus dorsi foram obtidos de animais selecionados de forma randomizada e insensibilizados de forma adequada (n=12) e inadequada (n=12). As amostras de carne foram avaliadas quanto ao pH, Capacidade de Retenção de Água (CRA). Do total de 3.347 suínos abatidos, 272 (8,13%) apresentaram pelo menos algum sinal de insensibilização inadequada. Observou-se que as 24 amostras de carne tiveram pH médio de 6,06, perda média de 24,74% de água e escore médio de 3,64 na escala de cor avaliada. O pH médio da carne obtida de animais inadequadamente insensibilizados (6,11) foi maior (p<0,05) que o pH médio de animais adequadamente insensibilizados (6,01). Quanto menor o pH da carne menor era o seu escore de cor e CRA (p<0,05). Portanto, a carne obtida de suínos mal insensibilizados possui maior pH, o que resulta em carne mais escura e com baixa CRA.(AU)
The objective of study was to evaluate the influence of inadequate sttuning during the swine slaughter in color, pH, and water loss of meat. After electric sttuning of animals in a slaugtherhouse under SIF of the Zona da Mata region, Minas Gerais, stunning parameters were evaluated in 3,347 slaughtered swines. The parameters evaluated were the absence of eyelid reflexes, ear reflexes, screams, pedaling in the forelimbs and arrhythmic breathing. After the full 16 hours of slaughter and storage of carcases in a cold chamber at 2°C, transverse fragments Longissimus dorsi muscle were obtained from randomly selected animals and properly (n=12) and improperly (n=12) sttuninged animals. The meat samples were evaluated for pH, Water Holding Capacity (WHC). Of the 3,347 slaughtered swines, 272 (8.13%) showed at least some sign of inadequate sttuning. It was observed that the 24 meat samples had mean pH of 6.06, mean loss water of 24.74% and mean score of 3.64 evaluated in color scale. The mean pH of meat obtained from animals improperly sttuninged (6.11) was greater (p<0.05) than the mean pH of animal properly sttuninged (6.01). The lower pH of meat causes lower color score and WHC (p<0.05). Therefore, the meat obtained from improperly sttuninged swine has a higher pH, which results in darker meat and low WHC.(AU)
Asunto(s)
Animales , Porcinos , Electrochoque/métodos , Electrochoque/veterinaria , Carne/análisis , Acidez , Sacrificio de Animales/métodosRESUMEN
Objetivou-se avaliar a influência da insensibilização inadequada durante o abate de suínos na cor, pH e perdas de água da carne. Após eletrocussão dos animais em um abatedouro-frigorífico sob SIF da região da Zona da Mata, Minas Gerais, parâmetros de insensibilização foram avaliados em 3.347 suínos abatidos. Os parâmetros avaliados foram ausência de reflexos palpebrais, reflexo de orelhas, gritos, pedalagem nos membros anteriores e respiração arrítmica. Após o completo abate e 16 horas de estocagem das carcaças em câmara fria a 2°C, fragmentos transversais do músculo Longissimus dorsi foram obtidos de animais selecionados de forma randomizada e insensibilizados de forma adequada (n=12) e inadequada (n=12). As amostras de carne foram avaliadas quanto ao pH, Capacidade de Retenção de Água (CRA). Do total de 3.347 suínos abatidos, 272 (8,13%) apresentaram pelo menos algum sinal de insensibilização inadequada. Observou-se que as 24 amostras de carne tiveram pH médio de 6,06, perda média de 24,74% de água e escore médio de 3,64 na escala de cor avaliada. O pH médio da carne obtida de animais inadequadamente insensibilizados (6,11) foi maior (p<0,05) que o pH médio de animais adequadamente insensibilizados (6,01). Quanto menor o pH da carne menor era o seu escore de cor e CRA (p<0,05). Portanto, a carne obtida de suínos mal insensibilizados possui maior pH, o que resulta em carne mais escura e com baixa CRA.
The objective of study was to evaluate the influence of inadequate sttuning during the swine slaughter in color, pH, and water loss of meat. After electric sttuning of animals in a slaugtherhouse under SIF of the Zona da Mata region, Minas Gerais, stunning parameters were evaluated in 3,347 slaughtered swines. The parameters evaluated were the absence of eyelid reflexes, ear reflexes, screams, pedaling in the forelimbs and arrhythmic breathing. After the full 16 hours of slaughter and storage of carcases in a cold chamber at 2°C, transverse fragments Longissimus dorsi muscle were obtained from randomly selected animals and properly (n=12) and improperly (n=12) sttuninged animals. The meat samples were evaluated for pH, Water Holding Capacity (WHC). Of the 3,347 slaughtered swines, 272 (8.13%) showed at least some sign of inadequate sttuning. It was observed that the 24 meat samples had mean pH of 6.06, mean loss water of 24.74% and mean score of 3.64 evaluated in color scale. The mean pH of meat obtained from animals improperly sttuninged (6.11) was greater (p<0.05) than the mean pH of animal properly sttuninged (6.01). The lower pH of meat causes lower color score and WHC (p<0.05). Therefore, the meat obtained from improperly sttuninged swine has a higher pH, which results in darker meat and low WHC.
Asunto(s)
Animales , Acidez , Carne/análisis , Electrochoque/métodos , Electrochoque/veterinaria , Porcinos , Sacrificio de Animales/métodosRESUMEN
INTRODUÇÃO: As queimaduras elétricas correspondem de 5 a 15% dos casos de acidentes com queimaduras. A maioria está associada a acidentes do trabalho, nos quais predominam as lesões com alta voltagem (acima de 1.000 Volts), em pacientes do sexo masculino. As taxas de mortalidade variam de 2 a 15%, nos mais diversos centros de queimados. O objetivo é revisar padronização das etapas cirúrgicas na fase aguda de desbridamento (primeiros 15 dias) pela comparação de dosagem de creatofosfoquinase, hidratação venosa e fotografias para a aplicação de uma rotina de etapas cirúrgicas. MÉTODOS: Trata-se de um estudo quantitativo, prospectivo, realizado em um hospital público da cidade de Fortaleza, CE, entre julho de 2013 a dezembro de 2015. A população foi composta por adultos jovens, entre 15 e 50 anos, de ambos os sexos, vítimas de queimaduras por choque elétrico, com lesão de terceiro grau, no mínimo muscular. RESULTADOS: Foram realizados 12 procedimentos cirúrgicos de amputações nos 15 pacientes do estudo (60%). Seis pacientes não sofreram amputação (40%). Um paciente sofreu três procedimentos de amputação no mesmo membro (pododáctilo, pé e coxa esquerdos) e outro, duas amputações em membros superiores distintos. CONCLUSÃO: O tratamento na fase aguda do choque elétrico deve incluir uma imediata e adequada reposição líquida venosa, associada com procedimentos cirúrgicos de desbridamentos e de amputações, o mais precoce possível, em etapas com intervalos de 48 a 72 horas.
INTRODUCTION: Electrical burns are responsible for 5% to 15% of cases of burn accidents. The majority is associated with workplace accidents, in which high-voltage injuries (>1,000 V) predominate in male patients. The mortality rates vary from 2% to 15% in different burn centers. The objective is to review the standardization of surgical steps in the acute phase of debridement (the first 15 days) by comparison of creatine phosphokinase levels, intravenous hydration, and photographs to implement routine surgical stages. METHODS: This was a quantitative, prospective study performed in a public hospital in the city of Fortaleza, Brazil, between July 2013 and December 2015. The population was composed of young adults between 15 and 50 years, of both sexes, who experienced electrical burns, with third-degree injuries and muscle involvement. RESULTS: Of the 15 patients in the study, 9 (60%) patients underwent 13 surgical amputation procedures and 6 (40%) patients did not undergo amputation. One patient underwent three amputation procedures in the same limb (toe, foot, and thigh) and another patient underwent two amputations in the upper limbs. CONCLUSION: Treatment in the acute phase of electrical shock must include immediate and adequate intravenous fluid replacement, along with surgical procedures of debridement and amputations, as early as possible, in steps with intervals of 48 to 72 hours.
Asunto(s)
Humanos , Masculino , Femenino , Adulto , Historia del Siglo XXI , Procedimientos Quirúrgicos Operativos , Heridas y Lesiones , Quemaduras por Electricidad , Estudios Prospectivos , Desbridamiento , Electrochoque , Estudios de Evaluación como Asunto , Fluidoterapia , Amputación Quirúrgica , Procedimientos Quirúrgicos Operativos/métodos , Procedimientos Quirúrgicos Operativos/estadística & datos numéricos , Heridas y Lesiones/cirugía , Heridas y Lesiones/complicaciones , Heridas y Lesiones/terapia , Quemaduras por Electricidad/cirugía , Quemaduras por Electricidad/complicaciones , Quemaduras por Electricidad/mortalidad , Quemaduras por Electricidad/terapia , Desbridamiento/métodos , Desbridamiento/normas , Electrochoque/métodos , Electrochoque/estadística & datos numéricos , Fluidoterapia/métodos , Amputación Quirúrgica/métodos , Amputación Quirúrgica/mortalidad , Amputación Quirúrgica/estadística & datos numéricosRESUMEN
OBJECTIVE: Homer1a is a protein that regulates metabotropic glutamate receptors involved in neural plasticity processes. Recently, we demonstrated that Homer1a mRNA is enhanced after pilocarpine-induced status epilepticus. Here, we investigated whether a single acute seizure triggered by means of pentylenetetrazole (PTZ) injection or maximal electroshock (MES) stimulation (2 different seizure models) would alter Homer1a expression in the hippocampus. METHODS: Male Wistar rats subjected to the PTZ or MES model were analyzed 2h, 8h, 24h, and 7days after seizure induction. Homer1a, mGluR1, and mGluR5 mRNA expression levels in hippocampal extracts were analyzed by quantitative PCR. RESULTS: Quantitative PCR revealed Homer1a overexpression at 2h after MES-induced tonic-clonic seizures compared to control, but the overexpression did not remain elevated after 8h. Pentylenetetrazole-induced seizures, in contrast, were not able to change Homer1a mRNA expression. No differences were observed at these time points after seizures for mGluR1 and mGluR5 mRNA expression in any of the models. SIGNIFICANCE: Our data indicate that the levels of Homer1a mRNA were transiently increased only after MES-induced tonic-clonic seizures (and not after PTZ-induced seizures). We suggest that Homer1a expression may be dependent on seizure intensity or on specific brain circuit activation. We suggest that Homer1a may contribute to counteract hyperexcitability processes.
Asunto(s)
Proteínas Portadoras/metabolismo , Convulsivantes/farmacología , Electrochoque/métodos , Pentilenotetrazol/farmacología , ARN Mensajero/metabolismo , Convulsiones/metabolismo , Animales , Anticonvulsivantes/uso terapéutico , Modelos Animales de Enfermedad , Proteínas de Andamiaje Homer , Masculino , Ratas , Ratas Wistar , Receptores de Glutamato Metabotrópico , Convulsiones/inducido químicamente , Convulsiones/etiologíaRESUMEN
This work evaluates the central nervous effects in ICR strain mice of 2-ethylthio-7-methyl-4-(4-methylphenyl)pyrazolo[1,5-a][1,3,5]triazine (MH4b1), a compound obtained by an efficient one-step reaction of S,S-diethyl 4-methylbenzoylimidodithiocarbonate with 5-amino-3-methyl-1H-pyrazole, in order to assess its neuro-pharmacological profile. The tests applied were: maximal electroshock seizure (MES), pentylenetetrazole (PTZ) seizures, forced swimming, plus maze, marble burying, sleeping time, rota-rod and catalepsy. In addition, MH4b1 binding to the benzodiazepine site of the GABA-A receptor and MH4b1 inhibition of monoamine oxidase (MAO) subtypes A and B were evaluated. MH4b1 showed anticonvulsant effects in a dose dependent manner (30-300 mg/kg, p.o.) against MES and inhibition of MAO-B (IC50: 24.5 µM) without activity at the benzodiazepine site. These data suggest that MH4b1 has anticonvulsant properties related to MAO-B inhibition.
Este trabalho avalia o efeito do 2-etiltio-7-metil-4-(4-metilfenil)pirazol[1,5-a][1,3,5]triazina (MH4b1) no sistema nervoso central de camundongos ICR. O MH4b1 foi obtido por a reação de 4-metilbenzoilimidoditiocarbonato de S,S-dietil e 5-amino-3-metil-1H-pirazol em uma única etapa. O perfil neurofarmacológico foi realizado por testes de convulsão induzida por eletrochoque (MES) e pentilenotetrazol (PTZ) e por testes de nado forçado, labirinto em cruz, esconder as esferas, sono barbitúrico, rota-rod e catalepsia. Também foi avaliada a união do MH4b1 ao o local de ligação de benzodiazepínicos do receptor GABA-A e a capacidade inibitória do MH4b1 sobre a monoaminoxidase (MAO) A e B. O MH4b1 mostrou efeito anticonvulsivante dependente da dose (30-300 mg) no teste do MES e apresentou atividade inibitória da MAO-B (CI50: 24.5 µM) sem interagir com o local de ligação de benzodiazepínicos do receptor. Os resultados sugerem que o MH4b1 tem atividade anticonvulsivante relacionada com a inibição da MAO-B.
Asunto(s)
Ratones , Pirazoles/farmacocinética , Convulsivantes/agonistas , Triazinas/farmacocinética , Electrochoque/métodos , Monoaminooxidasa/efectos de los fármacosRESUMEN
BACKGROUND: Cardiac dysfunction is one of the possible causes of sudden unexpected death in epilepsy (SUDEP). Therefore, it was the objective of this study to evaluate the cardiac and electrocardiographic parameters after seizures induced by maximal electroshock (MES) in Wistar rats. METHODS: Electroshock seizures were induced in Wistar rats through a pair of ear-clip electrodes (10 mA at a frequency of 60 Hz applied for one second). In vivo electrocardiography (ECG) was performed in awake animals for analysis of heart rate variability (HRV) and cardiac rhythm. Ex vivo the Langendorff technique was used to analyze cardiac function and observe the incidence and severity of reperfusion arrhythmias. RESULTS: Convulsive seizures triggered by MES induced profound abnormalities in cardiac rhythm with serious electrocardiographic changes including ST-elevation, bundle branch block, atrioventricular nodal escape rhythm and premature ventricular contractions. ECG analysis demonstrated a consistent period of postictal bradyarrhythmia resulting in a transiently irregular cardiac rhythm with highly variable and prolonged QRS complexes and RR, PR, QT and QTc intervals. HRV evaluation revealed an increase in the high-frequency range of the power, suggesting an imbalance in the autonomic control of the heart with a postictal enhancement of parasympathetic tone. In addition, we observed in isolated heart a decrease in systolic tone and an increase in the coronary flow, heart rate and incidence/duration of ischemia-reperfusion arrhythmias. CONCLUSION: The present study supports a relationship betweem seizures, cardiac dysfunction and cardiac arrhythmias. This relationship may partially account for the occurrence of SUDEP.
Asunto(s)
Arritmias Cardíacas/etiología , Arritmias Cardíacas/fisiopatología , Electrochoque/efectos adversos , Convulsiones/complicaciones , Convulsiones/fisiopatología , Animales , Electrocardiografía/métodos , Electrochoque/métodos , Masculino , Daño por Reperfusión Miocárdica/etiología , Daño por Reperfusión Miocárdica/fisiopatología , Ratas , Ratas WistarRESUMEN
It is well known that an emotionally arousing experience usually results in a robust and persistent memory trace. The present study explored the potential mechanisms involved in the influence of stress on the consolidation of a contextual fear memory in animals subjected to a weak fear training protocol, and whether pretreatment with intra-basolateral amygdala or systemic administration of midazolam (MDZ) prevents the potential stress-induced influence on fear memory formation. A previous restraint session facilitated fear retention, this effect was not due to a sensitized effect of restraint on the footshock experience. MDZ, both systemically or intra-basolateral amygdala infusion prior to the restraint, attenuated the stress-induced promoting influence on fear memory formation. In addition, stress exposure activated the ERK1/2 pathway in basolateral amygdala (BLA) after the weak training procedure but not after the immediate footshock protocol. Similar to our behavioral findings, MDZ attenuated stress-induced elevation of phospho-ERK2 (p-ERK2) in BLA following the acquisition session. Given that the activation of ERK1/2 pathway is essential for associative learning, we propose that stress-induced facilitation of p-ERK2 in BLA is an important mechanism for the promoting influence of stress on the consolidation of contextual fear memory.
Asunto(s)
Anestésicos Intravenosos/farmacología , Condicionamiento Psicológico/efectos de los fármacos , Miedo/efectos de los fármacos , Memoria/efectos de los fármacos , Midazolam/farmacología , Estrés Psicológico/tratamiento farmacológico , Amígdala del Cerebelo/efectos de los fármacos , Amígdala del Cerebelo/metabolismo , Animales , Condicionamiento Psicológico/fisiología , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Electrochoque/métodos , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Miedo/fisiología , Masculino , Ratas , Ratas Wistar , Factores de TiempoRESUMEN
The authors describe the frequency and characteristics of Cotard syndrome among neurological and psychiatric inpatients at a tertiary referral center. All inpatients from the National Institute of Neurology of Mexico (March 2007-May 2009) requiring neuropsychiatric consultation were reviewed. Among 1,321 inpatient consultations, 63.7% had neurological disease and one (0.11%) had viral encephalitis and Cotard syndrome. Of inpatients, 36.2% had pure psychiatric disorders and three (0.62%) had Cotard syndrome, associated with psychotic depression, depersonalization, and penile retraction (koro syndrome). This review discusses potential mechanisms for Cotard syndrome, including the role of a perceptual-emotional dissociation in self-misattribution in the deliré des negations.
Asunto(s)
Deluciones/complicaciones , Trastornos Mentales/complicaciones , Trastornos Mentales/psicología , Enfermedades del Sistema Nervioso/complicaciones , Enfermedades del Sistema Nervioso/psicología , Adolescente , Adulto , Anciano , Deluciones/diagnóstico , Deluciones/terapia , Electrochoque/métodos , Femenino , Humanos , Masculino , México , Persona de Mediana Edad , Observación , Escalas de Valoración Psiquiátrica , Estudios Retrospectivos , Adulto JovenRESUMEN
In rats, phospholipase A(2) (PLA(2)) activity was found to be increased in the hippocampus immediately after training and retrieval of a contextual fear conditioning paradigm (step-down inhibitory avoidance [IA] task). In the present study we investigated whether PLA(2) is also activated in the cerebral cortex of rats in association with contextual fear learning and retrieval. We observed that IA training induces a rapid (immediately after training) and long-lasting (3 h after training) activation of PLA(2) in both frontal and parietal cortices. However, immediately after retrieval (measured 24 h after training), PLA(2) activity was increased just in the parietal cortex. These findings suggest that PLA(2) activity is differentially required in the frontal and parietal cortices for the mechanisms of contextual learning and retrieval. Because reduced brain PLA(2) activity has been reported in Alzheimer disease, our results suggest that stimulation of PLA(2) activity may offer new treatment strategies for this disease.
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Reacción de Prevención/fisiología , Corteza Cerebral/enzimología , Condicionamiento Psicológico/fisiología , Recuerdo Mental/fisiología , Fosfolipasas A2/metabolismo , Análisis de Varianza , Animales , Conducta Animal , Corteza Cerebral/anatomía & histología , Electrochoque/métodos , Activación Enzimática/fisiología , Miedo , Modelos Lineales , Masculino , Ratas , Ratas Wistar , Factores de TiempoRESUMEN
Electroconvulsive shock (ECS) improves motor function in Parkinson's disease. In rats, ECS stimulates the expression of various factors some of which have been proposed to exert neuroprotective actions. We have investigated the effects of ECS on 6-hydroxydopamine (6-OHDA)-injected rats. Three weeks after a unilateral administration of 6-OHDA, 85-95% nigral dopaminergic neurons are lost. Chronic ECS prevented this cell loss, protect the nigrostriatal pathway (assessed by FloroGold retrograde labeling) and reduce motor impairment in 6-OHDA-treated animals. Injection of 6-OHDA caused loss of expression of glial cell-line derived neurotrophic factor (GDNF) in the substantia nigra. Chronic ECS completely prevented this loss of GDNF expression in 6-OHDA-treated animals. We also found that protected dopaminergic neurons co-express GDNF receptor proteins. These results strongly suggest that endogenous changes in GDNF expression may participate in the neuroprotective mechanism of ECS against 6-OHDA induced toxicity.
Asunto(s)
Dopamina/fisiología , Electrochoque/métodos , Neuronas/fisiología , Enfermedad de Parkinson/prevención & control , Animales , Supervivencia Celular/fisiología , Modelos Animales de Enfermedad , Masculino , Neuronas/patología , Enfermedad de Parkinson/patología , Ratas , Ratas WistarRESUMEN
Pavlovian contextual fear conditioning occurs when an aversive unconditional stimulus (US), such as a footshock, is presented to a rat shortly after it is placed in an experimental context. Contextual fear conditioning does not occur when the shock is presented immediately upon placement of the rat in the novel chamber. In the present study, the authors report that increasing either the number of immediate shock sessions (Experiment 1) or the immediate shock duration (Experiment 2) did not reverse this deficit. However, immediate shock seems to sensitize subsequent context conditioning (Experiment 3). These findings suggest that the associative deficit produced by immediate shock is not related to the rat's ability to process the footshock US.
Asunto(s)
Condicionamiento Clásico/fisiología , Miedo , Reacción Cataléptica de Congelación/fisiología , Choque/psicología , Animales , Conducta Animal , Electrochoque/métodos , Masculino , Trastornos de la Percepción , Distribución Aleatoria , Ratas , Ratas Long-Evans , Factores de TiempoRESUMEN
Mucopolysaccharidosis type I (MPS I) is a lysosomal storage disease that leads to neurodegeneration and neurological deficits, among other pathological and clinical consequences. The aim of the present study was to evaluate neurobehavioral parameters in a genetic mouse model of mucopolysaccharidosis type I (MPS I). During exploration of an open field, adult MPS I (Idua(-/-)) mice showed normal locomotion and anxiety but reduced number of rearings. Idua(-/-) mice performed normally in a novel object recognition memory task and showed normal short-term retention of inhibitory avoidance training. By contrast, long-term retention of inhibitory avoidance was impaired in Idua(-/-) mice. The deficit in inhibitory avoidance memory could not be attributed to reduced footshock reactivity. The results indicate that Idua(-/-) mice present deficits in long-term memory for aversive training and reduced exploratory behavior.
Asunto(s)
Reacción de Prevención/fisiología , Proteínas de la Membrana/deficiencia , Memoria/fisiología , Mucopolisacaridosis I/genética , Mucopolisacaridosis I/fisiopatología , Animales , Conducta Animal , Modelos Animales de Enfermedad , Electrochoque/métodos , Conducta Exploratoria/fisiología , Inhibición Psicológica , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Proteínas Citotóxicas Formadoras de Poros , Tiempo de Reacción/genética , Tiempo de Reacción/efectos de la radiación , Reconocimiento en Psicología/fisiología , Estadísticas no ParamétricasRESUMEN
Although many studies have investigated the function of cellular prion protein (PrPc), its physiologic role remains elusive. PrPc null mice have been reported to develop normally and to show normal performance in most behavioural tests. In the present study we investigated whether this also holds true after episodes of acute stress. PrPc gene ablated (Prnp0/0) and wild-type mice were subjected to restraint stress, electric foot shock, or swimming and compared with non-stressed animals. Immediately after the stressful situation, the anxiety levels and locomotion of the animals were measured using plus-maze and open-field tests. Among non-stressed animals, there was no significant difference in performance between Prnp0/0 and wild type animals in either test. However, after acute stress provoked by a foot shock or a swimming trial, Prnp0/0 animals showed a significant decrease in anxiety levels when compared with control animals. Moreover, after the swimming test, knockout mice presented decreased locomotion when compared to wild-type mice. Because of this observation, we also assessed both types of mice in a forced swimming test with the objective of better evaluating muscle function and found that Prnp0/0 animals presented reduced forced swimming capacity when compared to controls. As far as we know, this is the first report suggesting that cellular prion protein is involved in modulation of anxiety or muscular activity after acute psychic or physical stress.
Asunto(s)
Conducta Animal/fisiología , Proteínas PrPC/deficiencia , Estrés Psicológico/genética , Estrés Psicológico/fisiopatología , Análisis de Varianza , Animales , Electrochoque/métodos , Conducta Exploratoria/fisiología , Masculino , Aprendizaje por Laberinto/fisiología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Tiempo de Reacción/efectos de la radiación , Restricción Física/métodos , Natación/fisiologíaAsunto(s)
Humanos , Masculino , Femenino , Niño , Adolescente , Adulto , Persona de Mediana Edad , Electrochoque/efectos adversos , Electrochoque/métodos , Electrochoque/psicología , Trastorno Bipolar/terapia , Catatonia/terapia , Complicaciones del Embarazo , Enfermedades del Sistema Nervioso Central/complicacionesAsunto(s)
Humanos , Masculino , Femenino , Niño , Adolescente , Adulto , Persona de Mediana Edad , Electrochoque/efectos adversos , Electrochoque/métodos , Electrochoque/psicología , Catatonia/terapia , Complicaciones del Embarazo , Enfermedades del Sistema Nervioso Central/complicaciones , Trastorno Bipolar/terapiaRESUMEN
Animal studies examining the effects of stress upon brain serotonergic neurons have not presented a clearcut and consistent picture. One stressor that has been shown to exert a consistently strong effect on serotonin release and c-fos activation in the dorsal raphe nucleus of rats is a series of inescapable electrical shocks. Using immunohistochemical double labeling for c-fos activation and serotonin, we examined the effects of delivering 100 inescapable tailshocks to rats on serotonergic neuronal activation throughout the brainstem raphe system. This stimulus exerted a consistent and strong activation of the entire midline brain stem system of serotonergic neurons. The implications of these findings for animal models of human psychopathology are discussed.
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Electrochoque/métodos , Neuronas/efectos de la radiación , Núcleos del Rafe/efectos de la radiación , Serotonina/metabolismo , Animales , Recuento de Células , Inmunohistoquímica/métodos , Masculino , Neuronas/metabolismo , Proteínas Proto-Oncogénicas c-fos/metabolismo , Núcleos del Rafe/citología , Ratas , Ratas Sprague-DawleyRESUMEN
The neurochemical mechanisms involved in post-ictal antinociception remain to be elucidated. Application of electroconvulsive shock (ECS) to rats results in post-ictal antinociception. The objective of this study was to identify endogenous substances that could participate in antinociception during post-ictal depression induced by ECS (70 mA, 60 Hz, 1 s). Antinociception was measured by the rat paw-pressure test, in which increased sensitivity is induced by intraplantar injection of carrageenan. This test proved to be efficient in detecting the electroshock-induced antinociception. Intense post-ictal antinociception was observed over a period of 30 min after the end of the seizure. It was used nonspecific opioid and specific vasopressin antagonists and the prolactin (PRL) release inhibitor to test the reversal of antinociception. Administration of naloxone (5, 7.5 and 10 mg/kg) blocked the post-ictal antinociception. The V(1) (125 microg/kg) and V(2) (250 microg/kg) vasopressin receptor antagonists ([beta-mercapto-beta,beta-cyclopentamethylenepropionyl(1),O-Et-Tyr(2),Val(4),Arg(8)]-vasopressin and [adamantaneacetyl(1),O-Et-d-Tyr(2),Val(4),Abu(6),Arg(8,9)]-vasopressin) also inhibited the nociceptive response. The antinociception blockade was more intense after administration of the V(1) receptor antagonist. Bromocriptine (4, 8 and 12 mg/kg) was able to reverse antinociception behavior during the post-ictal period. Morphine (1, 2 and 4 mg/kg), vasopressin (12.5, 100 and 400 microg/kg) and prolactin (100, 200 and 400 microg/kg) administration promoted a higher nociceptive threshold. It was administered the three substances with their respective antagonists to verify the opioidergic pathway and vasopressin and prolactin release interactions, and as a positive control. We observed that the tested mediators were released in an independent manner, indicating no interference in which other.
Asunto(s)
Electrochoque , Narcóticos , Umbral del Dolor/fisiología , Prolactina/fisiología , Vasopresinas/fisiología , Animales , Antagonistas de los Receptores de Hormonas Antidiuréticas , Electrochoque/métodos , Masculino , Morfina/farmacología , Naloxona/farmacología , Narcóticos/farmacología , Dimensión del Dolor/efectos de los fármacos , Dimensión del Dolor/métodos , Umbral del Dolor/efectos de los fármacos , Prolactina/farmacología , Ratas , Ratas Wistar , Receptores de Vasopresinas/fisiologíaRESUMEN
Los registros eléctricos extracelulares, de campo, multicelulares u oligocelulares, aportan una mayor cantidad de información si las diferentes ondas que los constituyen son clasificadas para su adecuado análisis. Aquí se describe un dispositivo clasificador de bioseñales, basado en un circuito microcontrolador con la capacidad para usar dos criterios simultáneos (amplitud y período refractario) para la clasificación y dos salidas del tipo TTL. Los principales componentes usados fueron: un convertidor A/D ADC0834 y dos microcontroladores PIC16F84A-20 y PIC16F84A-10, siendo el coste total final del dispositivo menor a US$60. El circuito permite establecer dos umbrales de amplitud (alto y bajo) y, simultáneamente, fijar la duración del período de retardo (1 ó 1,5 ms) para excluír descargas de la misma amplitud no pertenecientes a la misma célula. Adicionalmente, posee una pantalla de cristal líquido para presentar los conteos correspondientes a los eventos clasificados. El dispositivo fue probado, tanto con señales combinadas generadas por dos estimuladores en frecuencias de 5 a 100Hz, como con registros extracelulares in vivo de neuronas del asta dorsal medular de ratas. El error máximo en la clasificación fue de 3,2 por ciento, aún en altas frecuencias de descarga. Las salidas son compatibles con los sistemas convencionales de registro y análisis en ordenadores. El circuito clasificador de bioseñales aquí descrito constituye una alternativa excelente y de bajo coste con amplia aplicación, tanto en neurociencias como en otras áreas de investigación básica y clínica.
Asunto(s)
Electrochoque/métodos , Electrocardiografía/efectos de la radiación , Espacio Extracelular/efectos de la radiación , Potenciales de AcciónRESUMEN
A single electroconvulsive shock (ECS) or a sham ECS was administered to male 3-4-month-old Wistar rats 1, 2, and 4 h before training in an inhibitory avoidance test and in cued classical fear conditioning (measured by means of freezing time in a new environment). ECS impaired inhibitory avoidance at all times and, at 1 or 2 h before training, reduced freezing time before and after re-presentation of the ECS. These results are interpreted as a transient conditioned stimulus (CS)-induced anxiolytic or analgesic effect lasting about 2 h after a single treatment, in addition to the known amnesic effect of the stimulus. This suggests that the effect of anterograde learning impairment is demonstrated unequivocally only when the analgesic/anxiolytic effect is over (about 4 h after ECS administration) and that this impairment of learning is selective, affecting inhibitory avoidance but not classical fear conditioning to a discrete stimulus.