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1.
Neurologia (Engl Ed) ; 37(4): 277-286, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-34531154

RESUMO

INTRODUCTION: Overpopulation and industrial growth result in an increase in air pollution, mainly due to suspended particulate matter and the formation of ozone. Repeated exposure to low doses of ozone, such as on a day with high air pollution levels, results in a state of chronic oxidative stress, causing the loss of dendritic spines, alterations in cerebral plasticity and in learning and memory mechanisms, and neuronal death and a loss of brain repair capacity. This has a direct impact on human health, increasing the incidence of chronic and degenerative diseases. DEVELOPMENT: We performed a search of the PubMed, Scopus, and Google Scholar databases for original articles and reviews published between 2000 and 2018 and addressing the main consequences of ozone exposure on synaptic plasticity, information processing in cognitive processes, and the alterations that may lead to the development of neurodegenerative diseases. CONCLUSIONS: This review describes one of the pathophysiological mechanisms of the effect of repeated exposure to low doses of ozone, which causes loss of synaptic plasticity by producing a state of chronic oxidative stress. This brain function is key to both information processing and the generation of structural changes in neuronal populations. We also address the effect of chronic ozone exposure on brain tissue and the close relationship between ozone pollution and the appearance and progression of neurodegenerative diseases.


Assuntos
Poluição do Ar , Doenças Neurodegenerativas , Ozônio , Poluição do Ar/efeitos adversos , Poluição do Ar/análise , Humanos , Doenças Neurodegenerativas/induzido quimicamente , Plasticidade Neuronal , Estresse Oxidativo , Ozônio/efeitos adversos
2.
Plant Biol (Stuttg) ; 23(6): 1044-1050, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34532929

RESUMO

Studies addressing the impact of herbivory in carnivorous plants are scarce, despite loss of tissue being expected to be costly, as leaves are involved in both energy and nutrient acquisition. We evaluated the effect of simulated herbivory in a population of the carnivorous plant Pinguicula moranensis. We predicted an overall negative impact of herbivory by reducing growth, flowering probability and survivorship. Specifically, we expected that the increase in the negative effect should be related to the amount of leaf area removed. We performed simulated herbivory in plants growing in situ (2015) and ex situ (greenhouse, 2016) using a paper punch (herbivory ranging from 0 to 50%). In the ex-situ experiment, we also tested the effect of availability of resources by implementing a prey addition trial where half of the plants were supplemented with prey (one fruit fly per week). In both experiments, our hypothesis was not supported, as growth, flowering probability and survivorship were not influenced by herbivory treatments. Plants subjected to prey addition did not show higher performance than plants deprived of prey, contradicting our prediction that availability of resources could ameliorate the effect of herbivory. Overall, the lack of differences in performance between undamaged (control) and damaged plants indicate an unexpected short-term ability of P. moranensis to tolerate herbivory, even at high levels of damage.


Assuntos
Planta Carnívora , Herbivoria , Folhas de Planta
3.
Vaccine ; 39(40): 5839-5844, 2021 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-34465476

RESUMO

BACKGROUND: Low vaccination rates and under-detection of pertussis infections in adolescents and young adults have an impact on the transmission of pertussis to infants. In this study, the proportion of adolescents and young adults with IgG antibodies against B. pertussis antigens, representing recent infection or vaccination, was estimated in a population-based probabilistic survey in Mexico. METHODS: Sera and data from 1,581 subjects, including 1,102 adolescents and 479 young adults (10-19 and 20-25 years old, respectively) randomly selected from Mexico's 2012 National Health and Nutrition Survey, were analyzed. IgG antibodies against pertussis toxin (PT) were measured with the CDC/FDA ELISA. A subset of 234 samples was additionally tested with Bp-IgG PT ELISA kit (EUROIMMUN AG, Lubeck, Germany). Threshold values from corresponding test kits were used to identify recent infection or vaccination. RESULTS: Overall anti-PT IgG seroprevalence was 3.9% (95% CI: 2.3-6.3); 3.1% (95% CI: 1.9-5.0) in adolescents, and 4.9% (95% CI: 2.2-11) in young adults. Seroprevalence did not significantly vary by sex, socioeconomic status, region or rural/urban location. Compared to the CDC/FDA ELISA, the EUROIMMUN test showed a 76% sensitivity and 88% specificity. The weighted estimates represent a considerable burden of recent infection in adolescents and young adults; however, most adolescents and adults were seronegative and, therefore, susceptible to pertussis infection. CONCLUSION: Since booster vaccination to B. pertussis after toddlerhood is not recommended in the Mexican national policy, anti-PT IgG seropositivity may be reasonably attributed to recent infection. Assessing pertussis seroprevalence requires careful consideration of the diagnostic test threshold interpretation and epidemiological model used.


Assuntos
Bordetella pertussis , Coqueluche , Adolescente , Humanos , Lactente , México/epidemiologia , Inquéritos Nutricionais , Estudos Soroepidemiológicos , Coqueluche/diagnóstico , Coqueluche/epidemiologia , Adulto Jovem
4.
Neurobiol Learn Mem ; 181: 107428, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33798697

RESUMO

Typical amnestic treatments are ineffective when administered to subjects trained in aversively-motivated tasks using relatively high foot-shock intensities. This effect has been found when treatments that disrupt neuronal activity are administered to different regions of the brain, including the amygdala. However, the molecular mechanisms induced by this intense training are unknown. We made a detailed mapping of c-Fos-expressing neurons in four regions of the amygdala after moderate and intense one-trial inhibitory avoidance training. Rats were sacrificed 90 min after training or after appropriate control procedures, and their brains were prepared for immunohistochemical c-Fos protein detection in the central, lateral, and in the anterior and posterior parts of the basolateral amygdaloid nucleus. We found a high percentage of neurons expressing c-Fos in the anterior part of the basolateral nucleus after moderate training, and this percentage increased further after intense training. Moderate and intense training did not induce changes in c-Fos expression in the other explored amygdaloid regions. These results show that inhibitory avoidance training produces a localized expression of c-Fos in the basolateral anterior nucleus of the amygdala, which is dependent upon the intensity of training, and indicate that synaptic plastic changes in this region may be required for the formation of memory of moderate and intense aversive learning.


Assuntos
Aprendizagem da Esquiva/fisiologia , Complexo Nuclear Basolateral da Amígdala/fisiologia , Neurônios/fisiologia , Animais , Complexo Nuclear Basolateral da Amígdala/metabolismo , Extinção Psicológica , Inibição Psicológica , Masculino , Memória/fisiologia , Neurônios/metabolismo , Proteínas Proto-Oncogênicas c-fos/metabolismo , Ratos
5.
Rev Sci Tech ; 39(1): 299-310, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32729557

RESUMO

This paper provides an overview of the importance of transparency at the World Trade Organization, a basic principle that translates into notification obligations. In particular, the paper details the related obligations under the Agreement on the Application of Sanitary and Phytosanitary Measures, and how it applies to trade in animals and animal products.


Les auteurs offrent une vue d'ensemble du rôle joué par la transparence au sein de l'Organisation mondiale du commerce, principe de base qui se traduit par une obligation de notification. En particulier, ils précisent les obligations prévues en vertu de l'Accord sur l'application des mesures sanitaires et phytosanitaires et la manière dont ce principe s'applique aux échanges internationaux d'animaux et de produits d'origine animale.


Los autores explican la importancia que dentro de la Organización Mundial del Comercio reviste la transparencia, un principio básico que se traduce en obligaciones de notificación. En particular, describen en detalle las obligaciones que en este sentido impone el Acuerdo sobre la Aplicación de Medidas Sanitarias y Fitosanitarias y cómo se aplica dicho principio al comercio de animales y productos de origen animal.


Assuntos
Comércio , Cooperação Internacional , Animais , Organizações
6.
Rev Sci Tech ; 39(1): 253-261, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32729562

RESUMO

World Trade Organization (WTO) Members have developed a framework of rules and guidance for veterinary control, inspection and approval procedures for international trade in animals and animal products. The core of this guidance can be found in Article 8 and Annex C of the Agreement on the Application of Sanitary and Phytosanitary Measures (SPS Agreement), which help Members to achieve the twin objectives of ensuring animal health and facilitating safe trade through their detailed disciplines. The issue of veterinary control, inspection and approval procedures frequently surfaces on the agenda of the Committee on Sanitary and Phytosanitary Measures when Members discuss trade concerns or decide to explore this topic in periodic reviews of the SPS Agreement. The WTO Trade Facilitation Agreement (2017), which was crafted to further expedite the movement and clearance of goods, brought additional structure to the design and operation of border procedures, including veterinary control procedures. The entry into force of the Trade Facilitation Agreement also increased, in many cases, the visibility and resources allocated to the operation of border controls, including international assistance. These processes provide further opportunities to enhance the profile of veterinary and other SPS agencies besides that of Customs, and to improve coordination among these various agencies and organisations.


Les Membres de l'Organisation mondiale du commerce (OMC) ont mis en place un cadre de règles et de directives concernant les procédures de contrôle vétérinaire, d'inspection et d'autorisation applicables aux échanges internationaux d'animaux et de produits d'origine animale. L'article 8 et l'annexe C de l'Accord sur l'application des mesures sanitaires et phytosanitaires (Accord SPS) constituent le coeur de ce dispositif destiné à aider les Membres à réaliser leur double objectif de protection de la santé animale et de facilitation d'un commerce sûr, grâce à un ensemble de disciplines définies de manière détaillée. La question des procédures de contrôle vétérinaire, d'inspection et d'autorisation refait régulièrement surface dans les délibérations du Comité des mesures sanitaires et phytosanitaires, par exemple lorsque les Membres abordent de nouveaux sujets d'inquiétude liés au commerce ou décident de réexaminer cet aspect à l'occasion des révisions périodiques de l'Accord SPS. Conçu pour accélérer le mouvement et le dédouanement des marchandises, l'Accord de l'OMC sur la facilitation des échanges (2017) s'est traduit par un meilleur agencement de la conception et de la mise en oeuvre concrète des procédures appliquées aux frontières, en particulier les procédures de contrôle vétérinaire. Dans bien des cas, l'entrée en vigueur de l'Accord sur la facilitation des échanges a également amélioré la visibilité des opérations de contrôle aux frontières ainsi que les ressources qui leur sont allouées, y compris dans le contexte de l'aide internationale. Ces processus ouvrent de nouvelles perspectives pour renforcer le profil non seulement des autorités douanières mais aussi des organismes chargés de la santé animale et des agences sanitaires et phytosanitaires et pour améliorer la coordination entre ces différentes agences et organisations.


Los Miembros de la Organización Mundial del Comercio (OMC) han elaborado un marco de referencia con reglas y pautas referidas a los procedimientos veterinarios de control, inspección y aprobación para el comercio internacional de animales y productos de origen animal. Los elementos básicos de estas orientaciones figuran en el artículo 8 y el Anexo C del Acuerdo sobre la Aplicación de Medidas Sanitarias y Fitosanitarias (Acuerdo MSF), que ayudan a los Miembros a cumplir dos objetivos indisociables: asegurar la sanidad animal y facilitar un comercio seguro gracias a las detalladas disciplinas que contienen. En el Comité de Medidas Sanitarias y Fitosanitarias se abordan a menudo cuestiones relativas a los procedimientos veterinarios de control, inspección y aprobación, cuando los Miembros tratan problemas comerciales o deciden estudiar el tema como parte del proceso de examen periódico del Acuerdo MSF. El Acuerdo de la OMC sobre Facilitación del Comercio (2017), elaborado con objeto de acelerar el movimiento de bienes y la correspondiente expedición de autorizaciones, introdujo una nueva estructura en la configuración y el funcionamiento de los procedimientos aduaneros, incluidos los de control veterinario. En muchos casos, la entrada en vigor del Acuerdo sobre Facilitación del Comercio también otorgó más protagonismo a la aplicación de controles fronterizos y llevó a destinarle un mayor volumen de recursos, entre otras cosas a través de la asistencia internacional. Estos procesos abren nuevas posibilidades para potenciar la función de los Servicios Veterinarios y otros servicios relacionados con las cuestiones sanitarias y fitosanitarias, además de los de aduanas, y para mejorar la coordinación entre estos diversos servicios, organismos y organizaciones.


Assuntos
Comércio , Cooperação Internacional , Animais , Internacionalidade , Organizações
7.
Neurologia (Engl Ed) ; 2019 Mar 08.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-30857788

RESUMO

INTRODUCTION: Overpopulation and industrial growth result in an increase in air pollution, mainly due to suspended particulate matter and the formation of ozone. Repeated exposure to low doses of ozone, such as on a day with high air pollution levels, results in a state of chronic oxidative stress, causing the loss of dendritic spines, alterations in cerebral plasticity and in learning and memory mechanisms, and neuronal death and a loss of brain repair capacity. This has a direct impact on human health, increasing the incidence of chronic and degenerative diseases. DEVELOPMENT: We performed a search of the PubMed, Scopus, and Google Scholar databases for original articles and reviews published between 2000 and 2018 and addressing the main consequences of ozone exposure on synaptic plasticity, information processing in cognitive processes, and the alterations that may lead to the development of neurodegenerative diseases. CONCLUSIONS: This review describes one of the pathophysiological mechanisms of the effect of repeated exposure to low doses of ozone, which causes loss of synaptic plasticity by producing a state of chronic oxidative stress. This brain function is key to both information processing and the generation of structural changes in neuronal populations. We also address the effect of chronic ozone exposure on brain tissue and the close relationship between ozone pollution and the appearance and progression of neurodegenerative diseases.

8.
Neuroscience ; 402: 1-10, 2019 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-30685541

RESUMO

The growth of many cities has generated an increase in the emission of environmental pollutants. Exposure to these pollutants has been associated with increased mortality worldwide. These pollutants, such as ozone, produce reactive oxygen species (ROS), which cause oxidative stress throughout the body. It has been observed that there is a relationship between chronic oxidative stress and the development of degenerative diseases typical of old age such as amyotrophic lateral sclerosis, Parkinson's disease, Alzheimer's disease, and Huntington's disease. The purpose of this research was to evaluate whether chronic exposure to ozone produces a deleterious effect on density and morphology of dendritic spines in CA1 of dorsal hippocampus and on learning and memory of object-place recognition. Rats were exposed to ozone or to ozone-free air for a period of 15, 30, 60, or 90 days. The principal results indicate that chronic oxidative stress induced by ozone produces a decrease in the density of dendritic spines, a decrease in thin and mushroom spine ratios, and an increase in stubby spine ratio, as well as a deficit in learning and memory of the object-place recognition task. These results indicate that chronic ozone exposure produces a loss in the inputs of CA1 neurons of the dorsal hippocampus, which may be the source of the cognitive deficits observed in the object-place recognition task, as indicated by the decrease in density of dendritic spines; these alterations are similar to those reported in some neurodegenerative diseases such as Alzheimer's disease.


Assuntos
Região CA1 Hipocampal/efeitos dos fármacos , Espinhas Dendríticas/efeitos dos fármacos , Ozônio/administração & dosagem , Células Piramidais/efeitos dos fármacos , Reconhecimento Psicológico/efeitos dos fármacos , Animais , Região CA1 Hipocampal/fisiologia , Espinhas Dendríticas/fisiologia , Masculino , Estresse Oxidativo , Células Piramidais/fisiologia , Ratos Wistar
9.
Plant Biol (Stuttg) ; 20(2): 205-212, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29083079

RESUMO

The interaction of plants with pollinators can be a determinant of their reproductive fitness. However, information about the pollination biology of carnivorous plants is scarce. To increase knowledge of reproductive ecology of carnivorous plants we focused on Pinguicula moranensis. Specifically, based on the presence of large, zygomorphic and spurred flowers, we predicted higher reproductive fitness in cross-pollinated than in self-pollinated flowers. Within a plot of 51 m2 we characterised the reproductive phenology, including flower lifespan and stigmatic receptivity. We identified pollinators and their movement patterns within the plot. Breeding system was experimentally evaluated using hand-pollination (i.e. autonomous, self- and cross-pollination). Flowers of P. moranensis were visited by long-tongued pollinators, mainly members of the Lepidoptera. Hand-pollination experiments confirmed our prediction and suggest that flower traits might favour cross-pollination. We mainly discuss the implications of the patchy distribution of plants and behaviour of pollinators on gene movement in this plant species, as pollination between genetically related individuals could be occurring.


Assuntos
Lamiales/fisiologia , Animais , Carnivoridade/fisiologia , Ecologia , Flores/fisiologia , Lepidópteros , Polinização/fisiologia , Reprodução/fisiologia
10.
Rev Esp Quimioter ; 30(5): 341-349, 2017 Oct.
Artigo em Espanhol | MEDLINE | ID: mdl-28718275

RESUMO

OBJECTIVE: The lack of adherence to antibiotic treatments is a matter of special interest, which has important clinical implications, as it is associated with therapeutic failure and increased bacterial resistance causing a high sani-tary cost. The objective of our study was to assess the degree of adherence to prescribed antibiotic treatment in outpatients through the detection of these in blood, urine or sputum. METHODS: Concentrations of antibiotics prescribed in 39 patients (34 with clinical suspicion of urinary tract infection and 5 with clinical suspicion of low respiratory tract infection) treated in Primary Care consultations of the Sanitary District of Almería (Spain) were determined by ultra-high performance liquid chromatography coupled to tandem mass spectrometry. RESULTS: A 48.7% of the patients did not comply correctly with the indicated treatment due to the complete or partial omission in taking the prescribed antibiotics. This lack of adherence was independent of the age and sex of the patients, the number of daily doses of the antibiotic, and whether or not they were receiving another medication. CONCLUSIONS: Precise analytical techniques such as liquid chromatography can be useful to detect inadequate or incomplete treatments as well as the degree of adherence of outpatients. Thus, adequate measures could be established that affect the control of therapeutic compliance.


Assuntos
Antibacterianos/análise , Antibacterianos/uso terapêutico , Adesão à Medicação/estatística & dados numéricos , Preparações Farmacêuticas/análise , Atenção Primária à Saúde/estatística & dados numéricos , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/administração & dosagem , Infecções Bacterianas/tratamento farmacológico , Cromatografia Líquida de Alta Pressão , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pacientes Ambulatoriais , Fatores Sexuais , Espanha , Escarro/química , Adulto Jovem
12.
Curr Alzheimer Res ; 12(3): 200-9, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25731625

RESUMO

Aging-related major neurocognitive disorder (NCD), formerly named dementia, comprises of the different acquired diseases whose primary deficit is impairment in cognitive functions such as complex attention, executive function, learning and memory, language, perceptual/motor skills, and social cognition, and that are related to specific brain regions and/or networks. According to its etiology, the most common subtypes of major NCDs are due to Alzheimer' s disease (AD), vascular disease (VaD), Lewy body disease (LBD), and frontotemporal lobar degeneration (FTLD). These pathologies are frequently present in mixed forms, i.e., AD plus VaD or AD plus LBD, thus diagnosed as due to multiple etiologies. In this paper, the definitions, criteria, pathologies, subtypes and genetic markers for the most common age-related major NCD subtypes are summarized. The current diagnostic criteria consider cognitive decline leading to major NCD or dementia as a progressive degenerative process with an underlying neuropathology that begins before the manifestation of symptoms. Biomarkers associated with this asymptomatic phase are being developed as accurate risk factor and biomarker assessments are fundamental to provide timely treatment since no treatments to prevent or cure NCD yet exist. Biological fluid assessment represents a safer, cheaper and less invasive method compared to contrast imaging studies to predict NCD appearance. Genetic factors particularly have a key role not only in predicting development of the disease but also the age of onset as well as the presentation of comorbidities that may contribute to the disease pathology and trigger synergistic mechanisms which may, in turn, accelerate the neurodegenerative process and its resultant behavioral and functional disorders.


Assuntos
Demência/genética , Demência/patologia , Marcadores Genéticos/genética , Demência/classificação , Humanos
13.
Br J Dermatol ; 172(5): 1303-7, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25244003

RESUMO

BACKGROUND: Dermatofibrosarcoma protuberans (DFSP) is an uncommon skin tumour with aggressive local growth. Whether DFSP should be treated with conventional surgery (CS) or Mohs micrographic surgery (MMS) has long been a topic of debate. OBJECTIVES: To calculate, in a large series of DFSP treated by MMS, the minimum margin that would have been needed to achieve complete clearance by CS. Secondly, to calculate the percentage of healthy tissue that was preserved by MMS rather than CS with 2- and 3-cm margins. METHODS: The minimum margin was calculated by measuring the largest distance from the visible edge of the tumour to the edge of the definitive surgical defect. Tumour and surgical defect areas for hypothetical CS with 2- and 3-cm margins were calculated using AutoCAD for Windows. RESULTS: A mean minimum margin of 1·34 cm was required to achieve complete clearance for the 74 tumours analysed. The mean percentages of skin spared using MMS rather than CS with 2- and 3-cm margins were 49·4% and 67·9%, respectively. CONCLUSIONS: MMS can achieve tumour clearance with smaller margins and greater preservation of healthy tissue than CS.


Assuntos
Dermatofibrossarcoma/cirurgia , Cirurgia de Mohs/métodos , Neoplasias Cutâneas/cirurgia , Adolescente , Adulto , Idoso , Dermatofibrossarcoma/patologia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/etiologia , Recidiva Local de Neoplasia/patologia , Neoplasias Cutâneas/patologia , Tempo para o Tratamento , Adulto Jovem
15.
J Eur Acad Dermatol Venereol ; 28(8): 1012-5, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23931335

RESUMO

BACKGROUND: Dermatofibrosarcoma protuberans (DFSP) is characterized by unpredictable subclinical extension, meaning that positive margins are frequently detected following conventional surgical excision. OBJECTIVE: To study the presence or absence of residual tumour in DFSP with positive margins after conventional surgery and identify possible predictors of residual tumour or clear margins following a single Mohs micrographic surgery (MMS) stage. METHODS: A retrospective study of patients with DFSP and positive margins following conventional excision referred for MMS was performed. We studied gender, age, tumour site, time from presentation to diagnosis, and affected margins. RESULTS: We studied 58 cases, 35 (60.3%) of which had histological evidence of residual tumour. Tumours of the head and neck were significantly associated with the persistence of tumour. A single MMS stage was sufficient to achieve clearance in the majority of cases (n = 46). All tumours with lateral involvement only were resolved with a single Mohs stage. CONCLUSIONS: DFSPs with positive margins after conventional surgical excision should undergo re-excision because the majority have histologic evidence of residual tumour. Re-excision with 1-cm margins beyond the scar could be an option in certain tumour sites, particularly when it is known which margins are involved.


Assuntos
Dermatofibrossarcoma/cirurgia , Cirurgia de Mohs , Adulto , Dermatofibrossarcoma/patologia , Feminino , Humanos , Masculino
16.
Brain Res ; 1369: 119-30, 2011 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-21070752

RESUMO

Dendritic spine density increases after spatial learning in hippocampal CA1 pyramidal neurons. Gonadal activity also regulates spine density, and abnormally low levels of circulating estrogens are associated with deficits in hippocampus-dependent tasks. To determine if gonadal activity influences behaviorally induced structural changes in CA1, we performed a morphometric analysis on rapid Golgi-stained tissue from ovariectomized (Ovx) and sham-operated (Sham) female rats 7 days after they were given a single water maze (WM) training session (hidden platform procedure) or a swimming session in the tank containing no platform (SC). We evaluated the density of different dendritic spine types (stubby, thin, and mushroom) in three segments (distal, medial, and proximal) of the principal apical dendrite from hippocampal CA1 pyramidal neurons. Performance in the WM task was impaired in Ovx animals compared to Sham controls. Total spine density increased after WM in Sham animals in the proximal and distal CA1 apical dendrite segments but not in the medial. Interestingly, mushroom spine density consistently increased in all CA1 segments after WM. As compared to the Sham group, SC-Ovx rats showed spine pruning in all the segments, but mushroom spine density did not change significantly. In Ovx rats, WM training increased the density of stubby and thin, but not mushroom spines. Thus, ovariectomy alone produces spine pruning, while spatial learning increases spine density in spite of ovariectomy. Finally, the results suggest that mushroom spine production in CA1 after spatial learning requires gonadal activity, whereas this activity is not required for mushroom spine maintenance.


Assuntos
Espinhas Dendríticas , Aprendizagem em Labirinto/fisiologia , Plasticidade Neuronal/fisiologia , Ovariectomia/efeitos adversos , Células Piramidais/citologia , Animais , Feminino , Ratos , Ratos Sprague-Dawley
17.
Rev Neurol ; 45(5): 284-92, 2007.
Artigo em Espanhol | MEDLINE | ID: mdl-17876740

RESUMO

INTRODUCTION: The theory of memory consolidation, based on the work published by Georg Elias Muller and Alfons Pilzecker over a century ago, continues to guide research into the neurobiology of memory, either directly or indirectly. In their classic monographic work, they concluded that fixing memory requires the passage of time (consolidation) and that memory is vulnerable during this period of consolidation, as symptoms of amnesia appear when brain functioning is interfered with before the consolidation process is completed. Most of the experimental data concerning this phenomenon strongly support the theory. DEVELOPMENT: In this article we present a review of experiments that have made it possible to put forward a model that explains the amnesia produced in conventional learning conditions, as well as another model related to the protection of memory when the same instances of learning are submitted to a situation involving intensive training. CONCLUSIONS: Findings from relatively recent studies have shown that treatments that typically produce amnesia when they are administered immediately after a learning experience (during the period in which the memory would be consolidating itself) no longer have any effect when the instances of learning involve a relatively large number of trials or training sessions, or relatively high intensity aversive events. These results are not congruent with the prevailing theories about consolidation.


Assuntos
Amnésia/fisiopatologia , Aprendizagem/fisiologia , Memória/fisiologia , Acetilcolina/metabolismo , Tonsila do Cerebelo/metabolismo , Catecolaminas/metabolismo , Córtex Cerebral/metabolismo , História do Século XX , História do Século XXI , Humanos , Modelos Biológicos , Serotonina/metabolismo , Substância Negra/metabolismo , Córtex Visual/metabolismo
18.
Opt Lett ; 31(21): 3137-9, 2006 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-17041660

RESUMO

We have numerically studied the cascade connection of a nonlinear amplifying loop mirror and a length of birefringent fiber with two linear polarizers. This structure is shown to work as a vector soliton switch under certain conditions. After optimizing each structure separately, we show the improvement of the switching response when the cascade connection is used. It is also demonstrated that this design acts as a good intensity filter for vector soliton pulses.

19.
Clin EEG Neurosci ; 37(3): 198-203, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16929704

RESUMO

This report is a 2-year follow-up to a previous study describing positive behavioral changes and a spurt of EEG maturation with theta/alpha neurofeedback (NFB) training in a group of Learning Disabled (LD) children. In a control paired group, treated with placebo, behavioral changes were not observed and the smaller maturational EEG changes observed were easily explained by increased age. Two years later, the EEG maturational lag in Control Group children increased, reaching abnormally high theta Relative Power values; the absence of positive behavioral changes continued and the neurological diagnosis remained LD. In contrast, after 2 years EEG maturation did continue in children who belonged to the Experimental Group with previous neurofeedback training; this was accompanied by positive behavioral changes, which were reflected in remission of LD symptoms.


Assuntos
Biorretroalimentação Psicológica/métodos , Transtornos do Comportamento Infantil/diagnóstico , Transtornos do Comportamento Infantil/prevenção & controle , Eletroencefalografia/métodos , Deficiências da Aprendizagem/diagnóstico , Deficiências da Aprendizagem/terapia , Criança , Transtornos do Comportamento Infantil/etiologia , Feminino , Seguimentos , Humanos , Deficiências da Aprendizagem/complicações , Masculino , Resultado do Tratamento
20.
J Chem Phys ; 123(20): 204706, 2005 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-16351292

RESUMO

Pulsed light-induced recording in azobenzene polymers has recently been studied due to its potential use in optical storage applications. In this paper we study the photoinduced birefringence (Deltan) and holographic grating recording in an azobenzene side chain liquid-crystalline polymethacrylate irradiating with a single 4 ns light pulse at 532 nm. For some irradiation conditions, Deltan grows in less than 50 ns reaching an essentially stable value of about 10(-2). Holographic gratings have been registered using intensity and polarization patterns. Fast response and stability, similar to those of Deltan, was observed in the holographic recording process. Both light-induced anisotropy and relief contributions have been found in the case of gratings recorded using intensity patterns, relief being the dominant contribution at high recording energies. Polarization gratings have been recorded using two orthogonally circularly polarized beams. The resultant gratings showed stable efficiencies up to 0.8% (measured at 633 nm in 1-mum-thick films) and no measurable relief was observed.

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