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1.
Trop Anim Health Prod ; 55(4): 260, 2023 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-37402941

RESUMO

The present experiment was aimed at finding the optimal supplemental dose of nano-selenium in broiler chicken during the summer season for better performance in terms of growth, blood metabolites, immune response, antioxidant status, and selenium concentration in vital organs. Three-hundred-day-old Vencobb broiler chicks were randomly distributed into five dietary treatment groups with six replicates of 10 chicks each. The dietary treatments were as follows: T1 (control group), basal diet; T2, basal diet with 0.0375 ppm of nano-Se; T3, basal diet with 0.075 ppm of nano-Se; T4, basal diet with 0.15 ppm of nano-Se; T5, basal diet with 0.3 ppm of nano-Se. The experiment was carried out for 35 days. The average gain and feed conversion ratio were best observed in T4 and T5. The antibody titres were significantly higher (P < 0.05) in the treated birds. At the 5th week, erythrocytic glutathione peroxidase, catalase, and superoxide dismutase activities were significantly (P < 0.05) higher and lipid peroxidation values were significantly (P < 0.05) lower in all the nano-Se-treated groups. The Se levels in the liver, breast muscle, kidney, brain, and gizzard were significantly (P < 0.05) increased with increased dietary nano-Se. Histological studies of the liver and kidney in the highest nano-Se-treated groups (T4 and T5) did not show any abnormal changes. It is concluded that supplementation of nano-selenium at 0.15 ppm over and above the basal level improved the performance and protect the birds from summer stress without any adverse effect on the vital organs of chicken.


Assuntos
Antioxidantes , Selênio , Animais , Antioxidantes/metabolismo , Selênio/metabolismo , Galinhas , Suplementos Nutricionais , Estações do Ano , Dieta/veterinária , Ração Animal/análise
2.
J Chem Phys ; 151(19): 191102, 2019 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-31757128

RESUMO

The addition of zinc complexes to the syntheses of indium phosphide nanocrystals (InP NCs) has become commonplace, due to their ability to alter and significantly improve observed optical properties. In this paper, the role of zinc complexes on the synthesis and observed properties of InP is carefully examined. Produced InP and InP:Zn2+ NCs are thoroughly characterized from both structural (core and surface) and optical perspectives over a wide range of Zn2+ compositions (0%-43% atomic content). We find no differences in the physical (NC size and polydispersity) and structural properties (crystallographic phase) of InP and InP:Zn2+ NCs. Optically, significant changes are observed when zinc is added to InP syntheses, including blueshifted absorption edges and maxima, increased quantum yields, and the near elimination of surface state emission. These improved optical properties result from surface passivation by zinc carboxylate moieties. Changes to the optical properties begin at zinc concentrations as low as 5%, demonstrating the high sensitivity of InP optical properties to exogenous species.

3.
Trop Anim Health Prod ; 49(2): 259-263, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27888394

RESUMO

A total of 60 animals (38 cows, 22 heifers) were selected and were divided into three groups of 20 animals each (containing both anoestrus and repeat breeder) in which treatment was performed for 60 days. Group I: control (farmer practice), T1 group: group I + hormone (double synch), and T2 group: group I + hormone (Estra double synch). The growth performances were measured in terms of body weight and average daily gain (ADG). Blood collection was done at the start and end of the experiment for assessment of blood biochemical, hematological, and reproductive status of the animals. Results revealed significant improvement in growth and reproductive performances in treatment group as compared to control group. Higher percentage of conception was achieved in group III (60%) followed by group II (55%). The least percentage was in group I (15%), i.e., in control group. So it was found that the effect of treating the reproductive-disordered animals with Estra double synch gave comparatively better result than double synch hormonal application.


Assuntos
Busserrelina/farmacologia , Bovinos/fisiologia , Indústria de Laticínios/métodos , Dinoprosta/análogos & derivados , Estradiol/análogos & derivados , Sincronização do Estro/efeitos dos fármacos , Substâncias para o Controle da Reprodução/farmacologia , Animais , Bovinos/crescimento & desenvolvimento , Dinoprosta/farmacologia , Estradiol/farmacologia , Feminino , Índia , Inseminação Artificial/veterinária , Reprodução
4.
Case Rep Psychiatry ; 2019: 3954161, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31428500

RESUMO

Energy drinks are nonalcoholic beverages that are widely consumed in the general population, and worldwide usage is increasing. The main stimulant component of energy drinks is typically caffeine. Few case reports exist that link energy drink consumption to psychosis, and similarly few reports exist that associate energy drink consumption with acute renal failure. We present a patient who simultaneously developed psychosis and acute renal failure associated with excessive energy drink consumption. The patient required haemodialysis, and his psychosis resolved on cessation of energy drinks and a brief course of antipsychotic medication. We perform a review of similar cases where excessive caffeinated energy drink consumption has been linked to psychosis or acute renal failure. To our knowledge, this is the first case report describing both renal failure and psychosis occurring simultaneously in a patient. Recognising the spectrum of disorders associated with excessive energy drink consumption is vital for both physicians and psychiatrists, as this has important implications for both prognosis and treatment.

5.
J Natl Cancer Inst ; 80(10): 769-72, 1988 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-3290499

RESUMO

Survival patterns of NBL/Up mice exposed to 675-800 R of total-body x-radiation depended on direction and rate of exposure. Homogeneous dual exposures administered at 126 R/minute were more effective than those administered at 63 R/minute. Dorsal and dual exposures at 63 R/minute were equally effective, while absorption reduced the effectiveness of ventral exposures. Since cellular repair of hematopoietic tissue was initiated only during exposure, increased homogeneity without increased exposure rate would not increase effectiveness. With rate, direction, and homogeneity influencing the effectiveness of total-body exposures, fallacies inherent in converting total-body exposures to absorbed tissue dose became apparent.


Assuntos
Radioterapia/métodos , Irradiação Corporal Total/métodos , Animais , Transferência de Energia , Feminino , Camundongos , Radioterapia/efeitos adversos , Dosagem Radioterapêutica , Irradiação Corporal Total/efeitos adversos
6.
Int J Dev Biol ; 45(1): 259-64, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11291855

RESUMO

Seven-transmembrane receptors of the frizzled family can interact with secreted Wnt ligands and transmit Wnt signals into the cell. Dependent on the ligand receptor combination, distinct Wnt pathways are activated. Xenopus frizzled 7 (Xfz7) and Xwnt-8b as well as Human frizzled 5 (Hfz5) and Xwnt-5a can act synergistically in the activation of Wnt/beta-catenin target genes siamois (Xsia) and nodal related 3 (Xnr3) and in the induction of ectopic axes in Xenopus embryos. In order to characterize the role of different protein domains of Xfz7 in Wnt/beta-catenin signaling, chimeric Xfz7/Hfz5 receptors were generated in which the extracellular (N5-TC7) or the intracellular domains (NT7-C5) between Xfz7 and Hfz5 were exchanged. We present evidence that the extracellular domain of Xfz7 can interact with Xwnt-5a and that the intracellular C-terminus can transmit a Wnt/beta-catenin signal. Despite these abilities, Xfz7 and Xwnt-5a do not act synergistically in the activation of Wnt/beta-catenin targets. This implies that the interaction of a frizzled receptor with different ligands can result in distinct cellular responses.


Assuntos
Receptores de Superfície Celular/fisiologia , Receptores Acoplados a Proteínas G , Proteínas de Xenopus , Xenopus/embriologia , Xenopus/fisiologia , Proteínas de Peixe-Zebra , Animais , Sequência de Bases , Primers do DNA/genética , Receptores Frizzled , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Estrutura Terciária de Proteína , Proteínas/genética , Proteínas/fisiologia , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/fisiologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores de Superfície Celular/química , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/metabolismo , Proteínas Recombinantes de Fusão/metabolismo , Transdução de Sinais , Proteínas Wnt , Proteína Wnt-5a , Xenopus/genética
7.
Pest Manag Sci ; 71(3): 395-403, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24771486

RESUMO

BACKGROUND: Given the physical properties of insecticides, there is often some movement of these compounds within crop plants following foliar application. In this context, movement of two formulations of cyantraniliprole, an anthranilic diamide, was characterized for translocation to new growth, distribution within a leaf and penetration through the leaf cuticle. RESULTS: Upward movement of cyantraniliprole to new plant growth via the xylem was confirmed using (14) C-radiolabeled cyantraniliprole and from Helicoverpa zea mortality on tomato leaves that had not been directly treated. Within a leaf there was significant acropetal movement (base to apex) of cyantraniliprole, but no significant basipetal movement (apex to base). Translaminar movement, the ability of a compound to penetrate the leaf cuticle, was demonstrated in a variety of plants, both with and without the use of adjuvants, by treating only the adaxial surface of the leaf and measuring control of diamondback moth (Plutella xylostella), green peach aphid (Myzus persicae) and sweetpotato whitefly (Bemisia tabaci) exposed in clip cages to the untreated abaxial surface. CONCLUSION: The plant mobility and plant protection of cyantraniliprole is discussed with implications for use in insect resistance management and integrated pest management programs.


Assuntos
Insetos/efeitos dos fármacos , Inseticidas/metabolismo , Folhas de Planta/parasitologia , Pirazóis/metabolismo , ortoaminobenzoatos/metabolismo , Animais , Afídeos/efeitos dos fármacos , Radioisótopos de Carbono , Hemípteros/efeitos dos fármacos , Inseticidas/farmacologia , Solanum lycopersicum/parasitologia , Mariposas/efeitos dos fármacos , Folhas de Planta/metabolismo , Plantas/metabolismo , Pirazóis/farmacologia , ortoaminobenzoatos/farmacologia
8.
Am J Clin Nutr ; 69(1): 13-7, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9925117

RESUMO

BACKGROUND: Previous studies showed that resting energy expenditure (REE) is lower in obese African American women than in obese white women. It is unknown, however, whether there are racial differences in how REE responds to weight loss and energy restriction. OBJECTIVE: We assessed REE, body composition, and respiratory quotient before and after weight loss in obese black and white women. DESIGN: We measured REE by indirect calorimetry and body composition by densitometry before and after 20-24 wk of treatment with a 3870-4289-kJ/d diet. Subjects were 109 obese females (24 black, 85 white) with a mean (+/-SD) body mass index (in kg/m2) of 36.3+/-5.0, weight of 95.7+/-12.6 kg, and age of 42.3+/-8.1 y. RESULTS: Before treatment, REE, adjusted for body composition, was significantly lower in black than in white subjects (P = 0.001). Black subjects lost significantly less weight during treatment than did white subjects (13.4+/-5.9 kg or 14.2+/-5.7% compared with 16.4+/-5.6 kg or 17.0+/-5.7%, respectively; P = 0.04). Analyses that controlled for initial REE and changes in fat mass and fat-free mass showed that blacks had significantly greater decreases in REE after treatment than did whites (9.9+/-7.3% compared with 6.3+/-7.4%; P = 0.02). CONCLUSION: This study suggests that weight loss results in greater reductions in REE in obese black women than in obese white women. These data underscore the need to consider both biological and behavioral factors when setting expectations and assessing outcomes for obesity treatment in African American women.


Assuntos
Metabolismo Basal , População Negra , Obesidade/etnologia , Redução de Peso , População Branca , Adulto , Análise de Variância , Composição Corporal , Calorimetria Indireta , Densitometria , Dieta , Feminino , Humanos , Pessoa de Meia-Idade , Obesidade/metabolismo
9.
Neuroscience ; 117(4): 1037-46, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12654355

RESUMO

Plastic changes in motor cortex capillary structure and function were examined in three separate experiments in adult rats following prolonged exercise. The first two experiments employed T-two-star (T(2)*)-weighted and flow-alternating inversion recovery (FAIR) functional magnetic resonance imaging to assess chronic changes in blood volume and flow as a result of exercise. The third experiment used an antibody against the CD61 integrin expressed on developing capillaries to determine if motor cortex capillaries undergo structural modifications. In experiment 1, T(2)*-weighted images of forelimb regions of motor cortex were obtained following 30 days of either repetitive activity on a running wheel or relative inactivity. The proton signal intensity was markedly reduced in the motor cortex of exercised animals compared with that of controls. This reduction was not attributable to alterations of vascular iron levels. These results are therefore most consistent with increased capillary perfusion or blood volume of forelimb regions of motor cortex. FAIR images acquired during experiment 2 under normocapnic and hypercapnic conditions indicated that resting cerebral blood flow was not altered under normal conditions but was elevated in response to high levels of CO(2), suggesting that prolonged exercise increases the size of a capillary reserve. Finally, the immunohistological data indicated that exercise induces robust growth of capillaries (angiogenesis) within 30 days from the onset of the exercise regimen. Analysis of other regions failed to find any changes in perfusion or capillary structure suggesting that this motor activity-induced plasticity may be specific to motor cortex.These data indicate that capillary growth occurs in motor areas of the cerebral cortex as a robust adaptation to prolonged motor activity. In addition to capillary growth, the vascular system also experiences heightened flow under conditions of activation. These changes are chronic and observable even in the anesthetized animal and are measurable using noninvasive techniques.


Assuntos
Capilares/crescimento & desenvolvimento , Artérias Cerebrais/crescimento & desenvolvimento , Circulação Cerebrovascular/fisiologia , Córtex Motor/irrigação sanguínea , Movimento/fisiologia , Neovascularização Fisiológica/fisiologia , Condicionamento Físico Animal/fisiologia , Envelhecimento/fisiologia , Animais , Volume Sanguíneo/fisiologia , Capilares/fisiologia , Dióxido de Carbono/metabolismo , Dióxido de Carbono/farmacologia , Artérias Cerebrais/fisiologia , Feminino , Hipercapnia/metabolismo , Imageamento por Ressonância Magnética , Masculino , Córtex Motor/fisiologia , Plasticidade Neuronal/fisiologia , Ratos , Ratos Long-Evans , Regulação para Cima/fisiologia
10.
Am J Med Genet ; 98(2): 161-7, 2001 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-11223852

RESUMO

Fragile-X syndrome is a common form of mental retardation resulting from the inability to produce the fragile-X mental retardation protein. Qualitative examination of human brain autopsy material has shown that fragile-X patients exhibit abnormal dendritic spine lengths and shapes on parieto-occipital neocortical pyramidal cells. Similar quantitative results have been obtained in fragile-X knockout mice, that have been engineered to lack the fragile-X mental retardation protein. Dendritic spines on layer V pyramidal cells of human temporal and visual cortices stained using the Golgi-Kopsch method were investigated. Quantitative analysis of dendritic spine length, morphology, and number was carried out on patients with fragile-X syndrome and normal age-matched controls. Fragile-X patients exhibited significantly more long dendritic spines and fewer short dendritic spines than did control subjects in both temporal and visual cortical areas. Similarly, fragile-X patients exhibited significantly more dendritic spines with an immature morphology and fewer with a more mature type morphology in both cortical areas. In addition, fragile-X patients had a higher density of dendritic spines than did controls on distal segments of apical and basilar dendrites in both cortical areas. Long dendritic spines with immature morphologies and elevated spine numbers are characteristic of early development or a lack of sensory experience. The fact that these characteristics are found in fragile-X patients throughout multiple cortical areas may suggest a global failure of normal dendritic spine maturation and or pruning during development that persists throughout adulthood.


Assuntos
Dendritos/patologia , Síndrome do Cromossomo X Frágil/patologia , Lobo Temporal/patologia , Córtex Visual/patologia , Adulto , Idoso , Humanos , Deficiência Intelectual/patologia , Masculino , Pessoa de Meia-Idade
11.
Brain Res Mol Brain Res ; 90(2): 101-9, 2001 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-11406288

RESUMO

Protein phosphatase 5 is a recently discovered Ser/Thr phosphatase that is structurally related to calcineurin and protein phosphatases 1 and 2. Northern blot and in situ hybridization studies have shown that protein phosphatase 5 mRNA is present at high levels in brain and is localized to discrete regions. In the present study, we used immunocytochemistry and immunoblot analyses to examine the regional and subcellular distribution of this enzyme in brain. Our work demonstrates that protein phosphatase 5 is widely expressed throughout brain, but is not uniformly distributed. The most intense staining occurred in neurons of the cerebellum, cerebral cortex, and the supraoptic nucleus of the hypothalamus. Other areas also contained immunoreactive cell bodies, including the globus pallidus, hippocampus, thalamus, lateral preoptic area of the hypothalamus, substantia nigra and other brainstem nuclei. Staining in these cells was observed primarily in perikarya and proximal processes.


Assuntos
Encéfalo/enzimologia , Proteínas Nucleares/análise , Proteínas Nucleares/genética , Fosfoproteínas Fosfatases/análise , Fosfoproteínas Fosfatases/genética , Animais , Especificidade de Anticorpos , Regulação Enzimológica da Expressão Gênica , Imuno-Histoquímica , Masculino , Proteínas Nucleares/imunologia , Fosfoproteínas Fosfatases/imunologia , RNA Mensageiro/análise , Ratos , Ratos Sprague-Dawley
12.
Behav Neurosci ; 103(1): 71-6, 1989 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-2923678

RESUMO

The effects of water deprivation on hippocampal responsiveness and behavior during nictitating membrane (NM) conditioning were assessed in 12 New Zealand White rabbits (Oryctolagus cuniculus). The results showed that water deprivation produced a significant shift in electroencephalographic (EEG) frequencies such that deprived rabbits had a higher proportion of 2-8 Hz activity than did ad-lib controls. In subsequent NM training, the rabbits took significantly fewer trials to reach criterion (M = 66 vs. M = 117). A correlation coefficient quantitatively describing the relation between pretraining EEG patterns and subsequent learning rate was highly significant (r = .84). Multiple-unit analyses indicated that deprivation enhanced hippocampal responsiveness to the conditioning stimuli, especially early in training. It was concluded that the hippocampus is responsive to motivational level and that one role of the hippocampus is in the nonassociative, modulatory processes that affect the rate of conditioning.


Assuntos
Condicionamento Clássico/fisiologia , Hipocampo/fisiologia , Aprendizagem/fisiologia , Membrana Nictitante/fisiologia , Privação de Água/fisiologia , Animais , Eletroencefalografia , Feminino , Masculino , Coelhos
13.
Behav Neurosci ; 110(5): 914-21, 1996 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8918995

RESUMO

Stimulating electrodes were implanted in rabbit cerebellum, providing an electrical conditioned stimulus (CS) activating cortical parallel fibers and thence Purkinje and other cells, and an electrical unconditioned stimulus (US) activating underlying white matter and eliciting unconditioned responses. Paired CS-US presentations led to the development of conditioned responses, which showed extinction following CS-alone trials and reacquisition with significant savings on reinstatement of paired trials. Increased local excitability as a result of paired training (but not following unpaired stimulus presentations) was observed in cerebellar cortex, as manifested in substantial decreases in CS threshold for response elicitation in all subjects. This preparation offers a model for the study of plastic neuronal interactions within cerebellar networks critically involved in associative learning.


Assuntos
Aprendizagem por Associação/fisiologia , Cerebelo/fisiologia , Condicionamento Clássico/fisiologia , Rede Nervosa/fisiologia , Plasticidade Neuronal/fisiologia , Animais , Mapeamento Encefálico , Córtex Cerebelar/fisiologia , Estimulação Elétrica , Masculino , Fibras Nervosas/fisiologia , Células de Purkinje/fisiologia , Coelhos
14.
Behav Neurosci ; 106(5): 739-50, 1992 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-1445654

RESUMO

Rabbits were implanted with chronic stimulating electrodes in white matter underlying lobule HVI of the cerebellar cortex. Stimulation elicited movements of the face or neck and, when paired with a tone conditioned stimulus (CS), produced learning comparable to that seen with peripheral unconditioned stimuli (USs). CS-alone trials produced extinction. Reinstatement of paired trials produced reacquisition with savings. Additional groups received either explicitly or randomly unpaired CS-US trials before paired conditioning. Low-frequency responding during these sessions indicated that the paired training results were associative and not due to pseudoconditioning or sensitization. Explicitly unpaired sessions retarded learning on subsequent paired trials compared with groups that received either randomly unpaired or no CS-US preexposure. These results are interpreted in terms of the role of the cerebellum and associated pathways in classical conditioning of motor responses.


Assuntos
Cerebelo/fisiologia , Condicionamento Clássico , Aprendizagem , Animais , Comportamento Animal , Estimulação Elétrica , Eletrodos Implantados , Humanos , Masculino , Vias Neurais , Células de Purkinje , Coelhos
15.
Behav Neurosci ; 108(1): 44-56, 1994 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8192850

RESUMO

The influence of water deprivation on hippocampal long-term potentiation (LTP), theta rhythm, and contextual fear conditioning in rats was examined. In Experiment 1, hippocampal EEG activity and perforant path LTP were assessed in pentobarbital-anesthetized rats. Water deprivation did not affect baseline cell excitability or low-frequency synaptic transmission in the dentate gyrus, but it increased the magnitude of perforant path LTP and elevated the proportion of theta rhythm in the EEG. In Experiment 2, rats were classically conditioned to fear a novel context through the use of aversive footshocks. Water deprivation facilitated the rate of contextual fear conditioning but did not alter the asymptote of learning. Experiment 3 demonstrated that the facilitation of contextual fear conditioning was not due to a change in unconditional shock sensitivity. These results suggest that water deprivation exerts an influence on contextual fear conditioning by modulating hippocampal LTP and theta rhythm and that these processes serve to encode contextual information during learning.


Assuntos
Aprendizagem por Associação/fisiologia , Condicionamento Clássico/fisiologia , Medo/fisiologia , Hipocampo/fisiologia , Potenciação de Longa Duração/fisiologia , Rememoração Mental/fisiologia , Meio Social , Ritmo Teta , Privação de Água/fisiologia , Animais , Nível de Alerta/fisiologia , Eletrochoque , Masculino , Motivação , Plasticidade Neuronal/fisiologia , Ratos , Receptores de N-Metil-D-Aspartato/fisiologia , Retenção Psicológica/fisiologia , Transmissão Sináptica/fisiologia
16.
Ann N Y Acad Sci ; 702: 27-39, 1993 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-8109877

RESUMO

The body of literature presented in this paper indicate, as Marr and Albus hypothesized, that the cerebellum is involved in the regulation of classical conditioning. At present, the most parsimonious hypothesis is that the essential memory traces for classical conditioning of eyelid closure, limb flexion, and other discrete responses learned with an aversive US are formed in cerebellar cortex and interpositus nucleus. Both sites contain neuronal elements which encode both conditioned and unconditioned stimuli. Recordings from both cerebellar cortex and the deep nuclei model the topography of the conditioned response and precede the response in time. Lesions of the cortex massively impair conditioning and lesions of the interpositus nucleus completely and permanently abolish the conditioned response without affecting reflex performance.


Assuntos
Cerebelo/fisiologia , Condicionamento Clássico/fisiologia , Modelos Neurológicos , Animais , Córtex Cerebelar/fisiologia , Núcleos Cerebelares/fisiologia , Humanos , Fibras Nervosas/fisiologia , Vias Neurais/fisiologia
17.
Behav Brain Res ; 110(1-2): 3-11, 2000 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-10802299

RESUMO

In 1942, Brogden and Gantt reported that electrical stimulation of cerebellar white matter elicited specific behavioral responses (limb flexion, eyeblink, etc.) and that these movements so elicited could easily be conditioned to a neural tone CS, using standard Pavlovian procedures. This early evidence for the key role of the cerebellum in learning of discrete movements has in recent years been replicated and much extended. It is now clear that the cerebellum is the essential structure for associative learning of discrete movements elicited by peripheral aversive or intracerebellar stimuli and that the memory traces so formed are stored in the cerebellum.


Assuntos
Comportamento Animal/fisiologia , Cerebelo/fisiologia , Condicionamento Clássico/fisiologia , Animais , Estimulação Elétrica , Humanos , Coelhos
18.
Brain Res ; 608(1): 150-4, 1993 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-8495339

RESUMO

Hippocampal CA1 unit responses were recorded during classical conditioning of rhythmic jaw movements in New Zealand White rabbits. Training was accomplished using a 1 kHz tone as the conditioned stimulus (CS) and 1 ml of sweetened water as the unconditioned stimulus (US). The interstimulus interval was 250 ms. Daily sessions consisted of 48 paired trials and six tone alone test trials, with an intertrial interval averaging 60 s. Controls were given explicitly unpaired stimuli. Unit and behavioral conditioned responses developed very rapidly in the trained group, but did not occur in controls. Averaged unit poststimulus histograms showed a correspondence between rhythmic cell discharges and the periodicity of the behavioral conditioned response after training. The results are discussed in relation to a hippocampal role in the modulation of learned movement patterns.


Assuntos
Condicionamento Palpebral/fisiologia , Hipocampo/fisiologia , Movimento/fisiologia , Plasticidade Neuronal/fisiologia , Animais , Feminino , Arcada Osseodentária/fisiologia , Masculino , Membrana Nictitante/fisiologia , Coelhos
19.
Brain Res ; 800(1): 48-61, 1998 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-9685583

RESUMO

The effects of complex motor task learning on subsequent motor performance of adult rats exposed to alcohol on postnatal days 4 through 9 were studied. Male and female Long-Evans rats were assigned to one of three treatments: (1) alcohol exposure (AE) via artificial rearing to 4.5.g kg-1 day-1 of ethanol in a binge-like manner (two consecutive feedings), (2) gastrostomy control (GC) fed isocaloric milk formula via artificial rearing, and (3) suckling control (SC), where pups remained with lactating dams. After completion of the treatments, the pups were fostered back to lactating dams, and after weaning they were raised in standard cages (two-three animals per cage) until they were 6 months old. Rats from each of the postnatal treatments then spent 20 days in one of three conditions: (1) inactive condition (IC), (2) motor control condition (MC) (running on a flat oval track), or (3) rehabilitation condition (RC) (learning to traverse a set of 10 elevated obstacles). After that all the animals were tested on three tasks, sensitive to balance and coordination deficits (parallel bars, rope climbing and traversing a rotating rod). On parallel bars, both male and female rats demonstrated the same pattern of outcomes: AE-IC rats made significantly more mistakes (slips and falls) than IC rats from both control groups. After 20 days of training in the RC condition, there were no differences between AE and both SC and GC animals in their ability to perform on the parallel bars test. On rope climbing, female animals showed a similar pattern of abilities: AE-IC rats were the worst group; exercising did not significantly improve the AE rats' ability to climb, whereas the RC groups (SC, GC and AE) all performed near asymptote and there were no significant differences among three neonatal treatment groups. There was a substantial effect of the male rats' heavier body weight on climbing ability, and this may have prevented the deficits in AE rats behavior from being detected. Nevertheless, male animals from all three postnatal treatments (SC, GC and AE) were significantly better on this task after RC. Female and male rats from all three postnatal groups demonstrated significantly better performance on the rotarod task after 20 days of 'rehabilitation'. These results suggest that complex motor skill learning improves some of the motor performance deficits produced by postnatal exposure to alcohol and can potentially serve as a model for rehabilitative intervention.


Assuntos
Envelhecimento/fisiologia , Intoxicação Alcoólica/fisiopatologia , Atividade Motora/fisiologia , Desempenho Psicomotor/fisiologia , Animais , Animais Recém-Nascidos , Etanol/sangue , Feminino , Lactação , Masculino , Ratos , Tempo de Reação , Caracteres Sexuais , Comportamento de Sucção
20.
Health Serv Res ; 12(4): 380-95, 1977.
Artigo em Inglês | MEDLINE | ID: mdl-591350

RESUMO

A model is described that predicts hospital census and computes, for each day, the number of elective admissions that will maximize the census over the short run, subject to constraints on the probability of overflow. Where a computer is available the model provides detailed predictions of census in units as small as 10 beds; used with manual computation the model allows production of tables of the recommended numbers of elective admissions to the hospital as a whole. The model has been tested in five hospitals and is part of the admissions system in two of them; implementation is described, and the results obtained are discussed.


Assuntos
Hospitais/estatística & dados numéricos , Modelos Teóricos , Computadores , Humanos , Admissão do Paciente
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