RESUMO
OBJECTIVE: To investigate the mitigating effects of administration of local anaesthetic or systemic meloxicam on the electroencephalographic (EEG) and cardiovascular responses during surgical castration of Bos indicus bull calves. STUDY DESIGN: Prospective, randomized, experimental study. ANIMALS: Thirty-six 6-8 month-old Bos indicus bull calves, with a mean ± standard deviation weight of 237 ± 19 kg. METHODS: Animals were allocated randomly to three groups of 12 (group L, 260 mg of 2% lidocaine subcutaneously and intratesticularly 5 minutes prior to castration; group M, 0.5 mg kg-1 of meloxicam subcutaneously 30 minutes prior to castration; group C, no preoperative analgesia administered). Anaesthesia was induced and maintained with halothane (0.9-1.1%) in oxygen. Electroencephalogram, heart rate (HR) and mean blood pressure (MAP) were recorded for 300 seconds prior to (baseline, B) and from the start of surgery (first testicle removal, T1). HR and MAP were compared at 10 second intervals for 90 seconds from the start of T1. Median frequency (F50), spectral edge frequency (F95) and total power of the EEG (Ptot) were analysed using area under the curve comparing T1 to B. RESULTS: All EEG variables were significantly different between B and T1 (p ≤ 0.0001). No differences in F50 were found between groups during T1 (p = 0.6491). F95 and Ptot were significantly different between group L and groups C and M during T1 (p = 0.0005 and 0.0163, respectively). There were transient significant changes in HR and MAP in groups L and M compared to group C during the 20-50 second periods. CONCLUSIONS: The EEG changes indicate nociceptive responses in all three groups during surgical castration, greater in group L compared to groups C and M. Both analgesics attenuated the peracute cardiovascular response. Lidocaine and meloxicam administered prior to castration attenuated these responses in Bos indicus bull calves. CLINICAL RELEVANCE: These findings provide support for the preoperative administration of lidocaine and potentially meloxicam for castration in Bos indicus bull calves.
Assuntos
Analgesia/veterinária , Anestesia Local/veterinária , Anestésicos Locais/administração & dosagem , Bovinos/cirurgia , Eletroencefalografia/veterinária , Lidocaína/administração & dosagem , Orquiectomia/veterinária , Tiazinas/administração & dosagem , Tiazóis/administração & dosagem , Analgesia/métodos , Anestesia Local/métodos , Animais , Gasometria/veterinária , Pressão Sanguínea/efeitos dos fármacos , Frequência Cardíaca/efeitos dos fármacos , Injeções Subcutâneas/veterinária , Meloxicam , Orquiectomia/efeitos adversosRESUMO
OBJECTIVE: To evaluate the efficacy of oral meloxicam, topical anaesthetic cream and cautery iron in mitigating acute nociceptive responses of pigs to tail docking. STUDY DESIGN: A prospective, randomized, controlled experimental study. ANIMALS: A total of 40 healthy Large WhitexLandrace pigs aged 21±1 days, weighing 6.1±0.9 kg. METHODS: Pigs were randomly assigned to one of four treatments (n=10 per treatment): CONTROL: docked using clippers without analgesia; MEL: docked using clippers after administration of oral meloxicam; EMLA: docked using clippers after application of topical anaesthetic cream; and CAUT: docked using a cautery iron without analgesia. Anaesthesia was induced and maintained with halothane in oxygen. Following induction, end-tidal halothane was stabilized at 0.95-1.05% and electroencephalograph (EEG) recording commenced. After 5 minutes of baseline data collection, tail docking was performed and recording continued for a further 10 minutes. The EEG summary variables median frequency (F50), 95% spectral edge frequency (F95) and total power (PTOT) were calculated for the baseline period and for consecutive 30-second intervals following docking. RESULTS: Following docking, F50 increased and PTOT decreased significantly in CONTROL and MEL pigs. EMLA pigs exhibited no change in any variable, whilst CAUT pigs exhibited a reduction in PTOT but no change in F50. F50 was higher in control pigs than in EMLA pigs 30-60 seconds after docking (p≤0.01). PTOT was lower in CONTROL than in EMLA pigs 30-90 seconds after docking (p<0.03) and in CAUT pigs 60 seconds after docking (p=0.01). CONCLUSIONS AND CLINICAL RELEVANCE: Prior application of EMLA cream abolished EEG indicators of nociception in pigs docked using clippers. Docking using a cautery iron without analgesia ameliorated EEG indicators of nociception, relative to using clippers without analgesia. Prior administration of EMLA cream or the use of cautery instead of clippers may reduce the acute pain experienced by pigs undergoing tail docking.
Assuntos
Dor Aguda/veterinária , Amputação Cirúrgica/veterinária , Analgésicos , Anestesia Local/veterinária , Anestésicos Locais , Eletroencefalografia/veterinária , Sus scrofa/cirurgia , Cauda/cirurgia , Tiazinas , Tiazóis , Dor Aguda/fisiopatologia , Dor Aguda/prevenção & controle , Administração Oral , Amputação Cirúrgica/instrumentação , Amputação Cirúrgica/métodos , Analgésicos/administração & dosagem , Anestesia Local/métodos , Anestésicos Locais/administração & dosagem , Animais , Anti-Infecciosos Locais , Feminino , Masculino , Meloxicam , Tiazinas/administração & dosagem , Tiazóis/administração & dosagemRESUMO
Limbs may fail to grow properly during fetal development, but the extent to which such growth alters the nervous system has not been extensively explored. Here we describe the organization of the somatosensory system in a 6-year-old monkey (Macaca radiata) born with a deformed left foot in comparison to the results from a normal monkey (Macaca fascicularis). Toes 1, 3, and 5 were missing, but the proximal parts of toes 2 and 4 were present. We used anatomical tracers to characterize the patterns of peripheral input to the spinal cord and brainstem, as well as between thalamus and cortex. We also determined the somatotopic organization of primary somatosensory area 3b of both hemispheres using multiunit electrophysiological recording. Tracers were subcutaneously injected into matching locations of each foot to reveal their representations within the lumbar spinal cord, and the gracile nucleus (GrN) of the brainstem. Tracers injected into the representations of the toes and plantar pads of cortical area 3b labeled neurons in the ventroposterior lateral nucleus (VPL) of the thalamus. Contrary to the orderly arrangement of the foot representation throughout the lemniscal pathway in the normal monkey, the plantar representation of the deformed foot was significantly expanded and intruded into the expected representations of toes in the spinal cord, GrN, VPL, and area 3b. We also observed abnormal representation of the intact foot in the ipsilateral spinal cord and contralateral area 3b. Thus, congenital malformation influences the somatotopic representation of the deformed as well as the intact foot.
Assuntos
Cérebro/fisiopatologia , Deformidades Congênitas do Pé/veterinária , Pé/inervação , Doenças dos Macacos/fisiopatologia , Plasticidade Neuronal , Córtex Somatossensorial/fisiopatologia , Potenciais de Ação , Animais , Mapeamento Encefálico/veterinária , Tronco Encefálico/fisiopatologia , Eletroencefalografia/veterinária , Deformidades Congênitas do Pé/fisiopatologia , Macaca fascicularis , Macaca radiata , Vias Neurais/fisiopatologia , Técnicas de Rastreamento Neuroanatômico/veterinária , Medula Espinal/fisiopatologia , Tálamo/fisiopatologiaRESUMO
OBJECTIVE: To describe epidemiological, clinical, and pathological features of neuroaxonal dystrophy in Quarter Horses (QHs) on a single farm. DESIGN: Prospective case series. Animals-148 horses. PROCEDURES: Neurologic, pathological, and toxicological evaluations were completed in selected neurologically affected horses over a 2-year period. Descriptive statistical analysis was performed. RESULTS: 87 QHs and 1 QH-crossbred horse were affected. Most (50/88 [56.8%]) affected horses were 1 to 2 years old (median age, 2 years [range, 2 months to 34 years]). Neurologic deficits included obtundation (53/88 [60%] horses), decreased to absent menace response (33/88 [37.5%]), proprioceptive positioning deficits, wide-based stance, ataxia, and dysmetria (88/88 [100%]). Most (78/88 [88.6%]) horses had mild ataxia, but some (10/88 [11.4%]) had moderate to severe ataxia. Low serum concentrations of vitamin E (≤ 2 mg/L) were detected in 3 index case horses and 16 of 17 randomly selected horses (13/14 affected and 3/3 unaffected) during study year 1. Dietary vitamin E supplementation did not improve neurologic deficits in affected horses; vitamin E administration in pregnant mares appeared to decrease but not prevent disease development among offspring born the following year. Lesions detected at necropsy included bilaterally symmetric neuroaxonal degeneration with axonal spheroids in the nucleus gracilis, nucleus cuneatus medialis, nucleus cuneatus lateralis, and nucleus thoracicus (5/5 horses). CONCLUSIONS AND CLINICAL RELEVANCE: Neuroaxonal dystrophy should be considered in evaluation of young horses with ataxia and proprioceptive positioning deficits. Vitamin E deficiency may contribute to disease severity.
Assuntos
Doenças dos Cavalos/etiologia , Distrofias Neuroaxonais/veterinária , Deficiência de Vitamina E/veterinária , Vitamina E/uso terapêutico , Envelhecimento , Animais , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Suplementos Nutricionais , Eletroencefalografia/veterinária , Feminino , Regulação da Expressão Gênica/fisiologia , Doenças dos Cavalos/tratamento farmacológico , Doenças dos Cavalos/patologia , Cavalos , Masculino , Distrofias Neuroaxonais/etiologia , Distrofias Neuroaxonais/patologia , Gravidez , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Deficiência de Vitamina E/complicações , Deficiência de Vitamina E/diagnóstico , Deficiência de Vitamina E/patologiaRESUMO
Auditory evoked potential (AEP) responses were recorded during echolocation in an Atlantic bottlenose dolphin (Tursiops truncatus) trained to accept suction-cup EEG electrodes and detect targets by echolocation. AEP recording was triggered by the echolocation clicks of the animal. Three targets with target strengths of -34, -28 and -22 dB were used at a target distance of 2 to 6.5 m for each target. The results demonstrated that the AEP appeared to both outgoing echolocation clicks and echoes during echolocation, with AEP complexes consisting of alternative positive and negative waves. The echo-related AEP amplitudes were obviously lower than the outgoing click-related AEP amplitudes for all the targets at the investigated target distances. However, for targets with target strengths of -22 and -28 dB, the peak-to-peak amplitudes of the echo-related AEPs were dependent on the target distances. The echo-related AEP response amplitudes increased at further target distances, demonstrating an overcompensation of echo attenuation with target distance in the echo-perception system of the dolphin biosonar. Measurement and analysis of outgoing click intensities showed that the click levels increased with target distance (R) by a factor of approximately 10 to 17.5 logR depending on target strength. The results demonstrated that a dual-component biosonar control system formed by intensity compensation behavior in both the transmission and receiving phases of a biosonar cycle exists synchronously in the dolphin biosonar system.
Assuntos
Golfinho Nariz-de-Garrafa/fisiologia , Ecolocação/fisiologia , Potenciais Evocados Auditivos , Estimulação Acústica/veterinária , Animais , Percepção Auditiva , Eletroencefalografia/veterinária , Feminino , HavaíRESUMO
The purpose of this study was to evaluate both, clinically and with electroencephalographic (EEG) recordings, the effect of gold wire implants in acupuncture points in dogs with uncontrolled idiopathic epileptic seizures. Fifteen dogs with such diagnosis were enrolled in the study. A first EEG recording was performed in all dogs under anaesthesia with xylazine (1mg/kg) and propofol (6 mg/kg) before the treatment protocol, and a second EEG was performed 15 weeks later. Relative frequency power, intrahemispheric coherence available through EEG, number of seizures and seizure severity were compared before and after treatment using a Wilcoxon signed-rank test. There were no significant statistical differences before and after treatment in relative power or in intrahemispheric coherence in the EEG recording. However, there was a significant mean difference in seizure frequency and seizure severity between control and treatment periods. After treatment, nine of the 15 dogs (60%) had at least a 50% reduction in seizures frequency during the 15 weeks established as follow-up of this treatment.
Assuntos
Terapia por Acupuntura/veterinária , Doenças do Cão/terapia , Epilepsias Mioclônicas/veterinária , Ouro/uso terapêutico , Convulsões/veterinária , Terapia por Acupuntura/métodos , Terapia por Acupuntura/normas , Animais , Doenças do Cão/diagnóstico , Doenças do Cão/fisiopatologia , Cães , Eletroencefalografia/veterinária , Epilepsias Mioclônicas/diagnóstico , Epilepsias Mioclônicas/fisiopatologia , Epilepsias Mioclônicas/terapia , Feminino , Masculino , Convulsões/diagnóstico , Convulsões/fisiopatologia , Convulsões/terapiaRESUMO
The model Tele-Stereo-EEG (continuous recording of intracerebral field potentials in the freely moving rat to produce an electropharmacogram) has been used to see if L-theanine- and theogallin-enriched decaffeinated green tea extract would change electrical brain activity after oral administration, to provide proof of access of active components to the brain via the blood-brain barrier. Baseline recording (45 min) was followed by a 5-h recording session after oral ingestion of the extract or single components: L-theanine, theogallin and quinic acid, a suggested metabolite of theogallin. Power spectra from Fast Fourier Transformed (FFT) field potential changes were divided into six frequency bands (delta, theta, alpha1, alpha2, beta1 and beta2). No effects could be measured using a saline solution for control purposes. Oral administration of 75 mg kg(-1) total extract led to power decreases mainly in delta and alpha2 frequencies during the first hour. This pattern has been observed in the presence of stimulatory synthetic compounds. Oral administration of 30 mg kg(-1) L-theanine led to power decreases of nearly all frequencies, being more pronounced during the second and following hours in comparison with the first hour. Ingestion of 20 mg kg(-1) theogallin also showed a power decreasing effect on cortical activity. Its possible metabolite quinic acid (10 mg kg(-1), p.o.) also produced decreases in delta, alpha2 and beta1 frequencies. Measurement of motion resulted in an increase during the first hour in the presence of theogallin and L-theanine. A tendential decrease was observed in the presence of L-theanine during the last hour at its presumably highest plasma levels. The results with the administration of the total extract provided evidence for the maior involvement of L-theanine and theogallin (or its presumable metabolite quinic acid) in its action, since no other active compounds were present in the extract. These compounds could be classified by comparison with reference drugs using discriminant analysis as being antidepressive and cognition enhancing, respectively. The extract appeared among those drugs having stimulatory effects.
Assuntos
Encéfalo/efeitos dos fármacos , Ácido Gálico/análogos & derivados , Glutamatos/farmacologia , Extratos Vegetais/química , Ácido Quínico/análogos & derivados , Chá/química , Administração Oral , Animais , Antidepressivos/farmacologia , Encéfalo/metabolismo , Cognição/efeitos dos fármacos , Eletroencefalografia/métodos , Eletroencefalografia/veterinária , Eletrofisiologia , Ácido Gálico/farmacologia , Ácido Quínico/farmacologia , Ratos , Ratos Endogâmicos F344RESUMO
The purpose of this study was to evaluate the antagonism of acupuncture-induced sedation by electroencephalographic spectral edge frequency (SEF) 95 in 10 healthy intact male Miniature Schnauzer dogs (4.2-6.1kg; 2-3 years old) without neurological disorder. The GV20 and Yintang acupoints were administered for 20 min. While the dogs were conscious, SEF 95 baseline values were recorded at 2-min intervals for 4 min. Then acupuncture was administered at the GV20 and Yintang acupoints. During the acupuncture procedure, the SEF 95 values were recorded at 2-min intervals for 10 min. Subsequently, antagonist drugs, naloxone and atipamezole, were administered through the cephalic vein. The SEF 95 values were then measured again at 2-min intervals for 10 min. Those values were found to be significantly increased after administration of atipamezole in dogs sedated by acupuncture at the GV20 and Yintang acupoints (p<0.05). However, the SEF 95 values in the naloxone groups did not show any significant changes before and after administration of the antagonist. It was concluded that sedation induced by acupuncture at the GV20 and Yintang acupoints might be partially associated with the alpha(2)-adrenergic system.
Assuntos
Analgesia por Acupuntura/veterinária , Encéfalo/efeitos dos fármacos , Encéfalo/fisiologia , Eletroencefalografia/veterinária , Imidazóis/farmacologia , Naloxona/farmacologia , Animais , Cães , Eletroencefalografia/efeitos dos fármacos , MasculinoRESUMO
We examined an epileptic focus by electroencephalography (EEG) by using an international 10-20 electrode system in 11 Shetland sheep dogs affected with familial idiopathic epilepsy. We also performed an evaluation of the amino acids in the cerebrospinal fluid (CSF) and a pathologic examination of the brains of 8 dogs that died from status epilepticus. Continuous electroencephalography demonstrated that an epileptic focus was initially detected in the frontal lobe, particularly the internal area, and that paroxysmal foci developed diffusely in other lobes of affected dogs with recurrent convulsions. The EEG analyses indicated spike and sharp wave complexes, which were considered to be paroxysmal discharges. An increased value for glutamate or aspartate was found in the CSF of some epileptic dogs. Histologically, acute neuronal necrosis and astrocytosis were distributed predominantly in the cingulate cortex and internal area of frontal cortex, less frequently in other areas of the cerebrum. The results of this study suggest that, initially, the dogs have an epileptic focus in the frontal lobe, and that the focus extends gradually to other areas of the cerebrum. Based on the distribution of neuronal necrosis and astrocytosis, acute neuronal damage may be related to the superexcitation of neurons following epilepsy.
Assuntos
Doenças do Cão/patologia , Epilepsia do Lobo Frontal/veterinária , Aminoácidos/líquido cefalorraquidiano , Animais , Encéfalo/patologia , Doenças do Cão/genética , Doenças do Cão/fisiopatologia , Cães , Eletroencefalografia/veterinária , Epilepsia do Lobo Frontal/genética , Epilepsia do Lobo Frontal/patologia , Epilepsia do Lobo Frontal/fisiopatologia , Feminino , Imuno-Histoquímica/veterinária , Masculino , LinhagemRESUMO
The direct and indirect effects of nitrous oxide (N2O) on the nociceptive responses of lumbar dorsal horn neurons, and the indirect effects on midbrain reticular formation (MRF) neurons and thalamic neurons were determined in goats anaesthetized with isoflurane. The technique used enabled the differential delivery of N2O to either the torso or the cerebral circulation, thus allowing assessment of the direct spinal and indirect brain effects of N2O. Systemic delivery of N2O appeared to have divergent effects, facilitating (4/11) or depressing (7/11) the responses of dorsal horn neurons. Such divergent effects were also observed when N2O was differentially delivered to the circulation in the torso (i.e. the spinal cord). Likewise, MRF and thalamic responses to noxious stimulation were variably affected by administration of N2O to the torso, with some cells facilitated (7/13 MRF neurons, 3/8 thalamic neurons) and others depressed (6/13 MRF neurons, 5/8 thalamic neurons). It appears that N2O has variable effects on the caprine CNS. The facilitatory action of N2O might partially explain why it is a relatively weak anaesthetic.
Assuntos
Anestésicos Inalatórios/farmacologia , Sistema Nervoso Central/efeitos dos fármacos , Cabras/fisiologia , Neurônios/efeitos dos fármacos , Óxido Nitroso/farmacologia , Animais , Sistema Nervoso Central/citologia , Sistema Nervoso Central/fisiologia , Depressão Química , Eletroencefalografia/veterinária , Isoflurano/farmacologia , Formação Reticular/citologia , Formação Reticular/efeitos dos fármacos , Formação Reticular/fisiologia , Medula Espinal/citologia , Medula Espinal/efeitos dos fármacos , Medula Espinal/fisiologia , Tálamo/citologia , Tálamo/efeitos dos fármacos , Tálamo/fisiologiaRESUMO
The EEG of Gallus domesticus was recorded before and after brain lesions following stimulation with light, sound and taste. 2. It was found that under the conditions of the experiment the lesions did not have any general effect on the arousal mechanism of the animal. 3. Bilateral lesions in the stratum cellulare externum of one animal had a specific effect on the arousal response to a quinine hydrochloride solution and it was concluded that it is possible to indicate deficits following brain lesion in the gustatory system using the EEG.