Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 517
Filtrar
1.
Pathologe ; 41(4): 406-410, 2020 Jul.
Artigo em Alemão | MEDLINE | ID: mdl-32472158

RESUMO

Proliferative changes seen in reactive mesothelial hyperplasia of a hydrocele sac may mimic malignant mesothelioma. There is no immunohistochemical staining that reliably separates benign from malignant mesothelial proliferations. However, the combined analysis of BAP1 by immunohistochemistry and CDKN2A by FISH has been reported to yield both a high specificity and sensitivity in this differential diagnosis. In addition, the evaluation of risk factors such as asbestos exposure or prior traumata may be helpful for the correct diagnosis. Exclusion of stromal invasion, which is diagnostic for malign mesothelioma, is of utmost importance. Therefore, extended histological workup is essential.


Assuntos
Neoplasias Pulmonares , Mesotelioma , Neoplasias Testiculares , Proliferação de Células , Diagnóstico Diferencial , Humanos , Imuno-Histoquímica , Neoplasias Pulmonares/diagnóstico , Masculino , Mesotelioma/diagnóstico , Neoplasias Testiculares/patologia , Testículo , Proteínas Supressoras de Tumor/análise , Ubiquitina Tiolesterase/análise
2.
Chirurg ; 90(12): 957-965, 2019 Dec.
Artigo em Alemão | MEDLINE | ID: mdl-31691141

RESUMO

The lymphatic system of the lungs is complex. To maintain an effective gas exchange there is a need for a dense lymphatic network. The alveolae have no lymphatic vessels. There is no segment-specific lymph drainage. For both lungs there are fixed bronchopulmonary lymph nodes but the number and size of the lymph nodes are variable. There are seven mediastinal lymph node chains that vary in extent, each of which acts as an independent functional unit. The accurate assessment of the nodal status needs a simple reproducible nodal map. The division into compartments or zones makes this easier. Mediastinal lymph node metastases without involvement of bronchopulmonary lymph nodes are possible. The development mechanism of this skip metastasizing is multifactorial.


Assuntos
Neoplasias Pulmonares , Linfonodos/anatomia & histologia , Humanos , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/cirurgia , Excisão de Linfonodo , Linfonodos/fisiologia , Metástase Linfática , Sistema Linfático/anatomia & histologia , Mediastino/anatomia & histologia , Estadiamento de Neoplasias
3.
J Bacteriol ; 199(14)2017 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-28507242

RESUMO

Under unfavorable growth conditions, bacteria enter stationary phase and can maintain cell viability over prolonged periods with no increase in cell number. To obtain insights into the regulatory mechanisms that allow bacteria to resume growth when conditions become favorable again (outgrowth), we performed global transcriptome analyses at different stages of growth for the alphaproteobacterium Rhodobacter sphaeroides The majority of genes were not differentially expressed across growth phases. After a short stationary phase (about 20 h after growth starts to slow down), only 7% of the genes showed altered expression (fold change of >1.6 or less than -1.6, corresponding to a log2 fold change of >0.65 or less than -0.65, respectively) compared to expression at exponential phase. Outgrowth induced a distinct response in gene expression which was strongly influenced by the length of the preceding stationary phase. After a long stationary phase (about 64 h after growth starts to slow down), a much larger number of genes (15.1%) was induced in outgrowth than after a short stationary phase (1.7%). Many of those genes are known members of the RpoHI/RpoHII regulons and have established functions in stress responses. A main effect of RpoHI on the transcriptome in outgrowth after a long stationary phase was confirmed. Growth experiments with mutant strains further support an important function in outgrowth after prolonged stationary phase for the RpoHI and RpoHII sigma factors.IMPORTANCE In natural environments, the growth of bacteria is limited mostly by lack of nutrients or other unfavorable conditions. It is important for bacterial populations to efficiently resume growth after being in stationary phase, which may last for long periods. Most previous studies on growth-phase-dependent gene expression did not address outgrowth after stationary phase. This study on growth-phase-dependent gene regulation in a model alphaproteobacterium reveals, for the first time, that the length of the stationary phase strongly impacts the transcriptome during outgrowth. The alternative sigma factors RpoHI and RpoHII, which are important regulators of stress responses in alphaproteobacteria, play a major role during outgrowth following prolonged stationary phase. These findings provide the first insight into the regulatory mechanisms enabling efficient outgrowth.


Assuntos
Proteínas de Bactérias/metabolismo , Regulação Bacteriana da Expressão Gênica/fisiologia , Rhodobacter sphaeroides/metabolismo , Proteínas de Bactérias/genética , Sequência de Bases , Divisão Celular , Sobrevivência Celular , DNA Bacteriano , Regiões Promotoras Genéticas , Rhodobacter sphaeroides/citologia , Rhodobacter sphaeroides/genética , Ativação Transcricional , Transcriptoma
4.
Pathologe ; 38(1): 45-47, 2017 Feb.
Artigo em Alemão | MEDLINE | ID: mdl-27885377

RESUMO

The autopsy of a fetus at 23 weeks gestational age revealed a partial pericardial defect with subsequent herniation of parts of the left ventricle. The myocard was impinged by the fibrous rim of the residual pericardium. Microscopic examination showed signs of recurrent myocardial infarctions with necrosis, calcification, fibrosis and prominent deposition of iron.Partial pericardial defects result from incomplete fusion of the pleuropericardial membrane and may lead to myocardial infarction via compression of the coronary arteries.


Assuntos
Divertículo/patologia , Cardiopatias Congênitas/patologia , Infarto do Miocárdio/congênito , Infarto do Miocárdio/patologia , Pericárdio/anormalidades , Pericárdio/patologia , Diagnóstico Pré-Natal , Aborto Eugênico , Adulto , Feminino , Humanos , Hidropisia Fetal/patologia , Miocárdio/patologia , Gravidez , Segundo Trimestre da Gravidez
5.
Skin Res Technol ; 22(4): 470-478, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26991667

RESUMO

BACKGROUND/PURPOSE: Neurophysiologic data on reactions of the human brain towards tactile stimuli evoked by fabrics moved on the skin are scarce. Furthermore, evaluation of fabrics' pleasantness using questionnaires suffers subjective biases. That is why we used a 64-channel electroencephalography (EEG) to objectively evaluate real-time brain reactions to fabric-skin interactions. METHODS: Tactile stimuli were triggered by selected fabrics of different qualities, i.e. modal/polyamide single jersey, cotton double rib and a jute fabric, applied hidden to either the palm or forearm of 24 subjects via a custom-made fabric-to-skin applicator called SOFIA. One-way anova analysis was carried out to verify the EEG data. RESULTS: The modal/polyamide fabric applied to the forearm and palm led to slightly stronger emotional valence scores in the brain than the conventional or baseline fabric. Furthermore, the single jersey elicits significant higher event-related potential (ERP) signals in all subjects when applied to the forearm, suggesting less distraction and better cognitive resources during the fabric/skin interaction. The brain thus reacts with instantaneous ERP to tactile stimulation of fabrics and is able to discriminate different qualities via implicit preferences. CONCLUSION: The test procedure described here may be a tool to evaluate the fabric feel with the exclusion of subjective biases.


Assuntos
Vestuário , Eletroencefalografia/métodos , Potenciais Evocados P300/fisiologia , Estimulação Física/métodos , Fenômenos Fisiológicos da Pele , Têxteis/análise , Tato/fisiologia , Adolescente , Adulto , Potenciais Somatossensoriais Evocados/fisiologia , Humanos , Pessoa de Meia-Idade , Pele/inervação , Propriedades de Superfície , Têxteis/classificação , Adulto Jovem
6.
Pathologe ; 35(6): 586-90, 2014 Nov.
Artigo em Alemão | MEDLINE | ID: mdl-25304423

RESUMO

The World Health Organization (WHO) classification differentiates between pleural tumors of mesothelial and mesenchymal origin as well as lymphoproliferative disorders, with malignant mesotheliomas forming the most common pleural primary tumor. Histologically, epithelioid (40-60 %), sarcomatoid (20-40 %), and biphasic mesotheliomas (20-40 %) are distinguished. The certain morphological diagnosis of a malignant pleural mesothelioma requires the establishment of mesothelial differentiation by means of an appropriate panel of antibodies to exclude pleural dissemination of a pulmonary or extrapulmonary epithelial malignancy and also requires the establishment of at least focal invasive growth to distinguish from reactive mesothelial proliferation. The exclusion of a malignant pleural mesothelioma may induce further differential diagnostic considerations, e. g. concerning the assignment to a certain primary tumor after the establishment of carcinomatous pleuritis.


Assuntos
Mesotelioma/diagnóstico , Mesotelioma/patologia , Neoplasias Pleurais/diagnóstico , Neoplasias Pleurais/patologia , Diagnóstico Diferencial , Humanos , Pulmão/patologia , Mesotelioma/classificação , Invasividade Neoplásica/patologia , Pleura/patologia , Neoplasias Pleurais/classificação , Prognóstico
7.
Pathologe ; 35(6): 612-4, 2014 Nov.
Artigo em Alemão | MEDLINE | ID: mdl-25326189

RESUMO

Giant cell interstitial pneumonia (GIP)-like pulmonary alterations as a special form of condensate pneumopathy may result following inhalation of certain types of tobacco smoke which can cause a pitfall diagnosis of sideropneumoconiosis or hard metal lung disease. Exact information regarding the patient occupation and smoking history and especially regarding the origin of the cigarettes helps to clarify the findings.


Assuntos
Células Gigantes/patologia , Doenças Pulmonares Intersticiais/patologia , Siderose/patologia , Fumar/efeitos adversos , Fumar/patologia , Adulto , Biópsia , Diagnóstico Diferencial , Humanos , Pulmão/patologia , Macrófagos Alveolares/patologia , Masculino , Microscopia Eletrônica , Pessoa de Meia-Idade
10.
Pathologe ; 34(6): 566-8, 2013 Nov.
Artigo em Alemão | MEDLINE | ID: mdl-24154755

RESUMO

A 67-year-old man presented with a poorly differentiated squamous cell carcinoma of the esophagus diagnosed by biopsy. After neoadjuvant radiochemotherapy the gastroesophagectomy specimen showed diffuse polymorphic and anuclear cell residues ranging from 35 µm to 46 µm in size. Immunohistochemically, PanCK and AE1-3 revealed a positive staining while CD68 and MIB1 showed a negative staining. The retrospective anamnesis revealed that the patient had chronic polyarthritis as underlying illness, for which reason he had been taking humira and methotrexate, a cytostatic drug, for many years. Therefore, the development of the tumor might have been enhanced by these drugs. Electron microscopic analysis confirmed that the avital akaryote cell residues represented a special type of tumor regression. Complete tumor regression level IV without vital rest tumor tissue based on Baldus et al. was diagnosed.


Assuntos
Carcinoma de Células Escamosas/patologia , Neoplasias Esofágicas/patologia , Regressão Neoplásica Espontânea/patologia , Neoplasia Residual/patologia , Adalimumab , Idoso , Anticorpos Monoclonais Humanizados/efeitos adversos , Anticorpos Monoclonais Humanizados/uso terapêutico , Antimetabólitos Antineoplásicos/efeitos adversos , Antimetabólitos Antineoplásicos/uso terapêutico , Antirreumáticos/efeitos adversos , Antirreumáticos/uso terapêutico , Artrite Reumatoide/tratamento farmacológico , Biópsia , Carcinoma de Células Escamosas/induzido quimicamente , Carcinoma de Células Escamosas/terapia , Transformação Celular Neoplásica/efeitos dos fármacos , Transformação Celular Neoplásica/patologia , Quimiorradioterapia Adjuvante , Terapia Combinada , Neoplasias Esofágicas/induzido quimicamente , Neoplasias Esofágicas/terapia , Esofagectomia , Esôfago/efeitos dos fármacos , Esôfago/patologia , Gastrectomia , Humanos , Assistência de Longa Duração , Masculino , Metotrexato/efeitos adversos , Metotrexato/uso terapêutico , Microscopia Eletrônica , Neoplasia Residual/induzido quimicamente , Neoplasia Residual/terapia
11.
Transpl Infect Dis ; 15(3): E97-E101, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23551689

RESUMO

Respiratory viruses are an important yet underestimated cause of infectious morbidity and mortality in immunocompromised children and adolescents. Here, we report the occurrence of fatal lower respiratory tract disease associated with human metapneumovirus (HMPV) infection in a 10-year-old girl with chronic graft-versus-host disease following allogeneic hematopoietic stem cell transplantation (HSCT) for secondary chronic myeloid leukemia. Symptoms occurred 8 months after HSCT while on immunosuppression with 0.2 mg/kg/day of prednisone, and presented as dry cough, bilateral pneumonitis, and progressive respiratory distress. Non-invasive and invasive microbiological investigations revealed HMPV type B as the sole pathogen. Histopathological findings showed interstitial and intra-alveolar pneumonitis with profound alveolar cell damage. The patient was treated with intravenous and oral ribavirin and polyvalent immunoglobulins, but ultimately died from respiratory failure. The case reflects the potentially fatal impact of infections by respiratory viruses in immunocompromised patients and the need for effective approaches to their prevention and treatment.


Assuntos
Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Metapneumovirus/isolamento & purificação , Infecções por Paramyxoviridae/virologia , Infecções Respiratórias/virologia , Criança , Evolução Fatal , Feminino , Doença Enxerto-Hospedeiro/complicações , Humanos , Hospedeiro Imunocomprometido , Leucemia Mielogênica Crônica BCR-ABL Positiva/terapia , Infecções por Paramyxoviridae/complicações , Infecções por Paramyxoviridae/diagnóstico , Infecções por Paramyxoviridae/patologia , Infecções Respiratórias/complicações , Infecções Respiratórias/diagnóstico , Infecções Respiratórias/patologia , Transplante Homólogo/efeitos adversos
12.
Pathologe ; 34(4): 338-42, 2013 Jul.
Artigo em Alemão | MEDLINE | ID: mdl-23263441

RESUMO

Benign epithelial tumors of the tracheobronchial system and the lungs are exceedingly rare. These entities encompass squamous and glandular papillomas (as well as their mixed forms) and adenomas (alveolar adenoma, papillary adenoma, salivary gland-like pleomorphic and mucinous adenomas and mucinous cystadenomas). These tumors are considered to be biologically benign neoplasms; however, they can pose considerable diagnostic difficulties, especially during frozen section evaluation, as they can mimic malignant tumors and in particular they can resemble well differentiated papillary adenocarcinomas. As a result of the extreme rarity of these tumors only a few descriptive diagnostic series exist and a systematic investigation including molecular data does not exist. This article presents the case of a 64-year-old patient with a glandular papilloma of the right main bronchus including the immunohistochemical and molecular work-up as well as a review of the current literature.


Assuntos
Neoplasias Brônquicas/genética , Neoplasias Brônquicas/patologia , Éxons/genética , Mutação/genética , Papiloma/genética , Proteínas Proto-Oncogênicas/genética , Proteínas ras/genética , Adenocarcinoma Papilar/genética , Adenocarcinoma Papilar/patologia , Substituição de Aminoácidos/genética , Asparagina/genética , Brônquios/patologia , Brônquios/cirurgia , Neoplasias Brônquicas/cirurgia , Broncoscopia , Diagnóstico Diferencial , Receptores ErbB/genética , Feminino , Secções Congeladas , Glicina/genética , Humanos , Pessoa de Meia-Idade , Papiloma/patologia , Papiloma/cirurgia , Pneumonectomia , Proteínas Proto-Oncogênicas p21(ras) , Análise de Sequência de DNA , Proteína Supressora de Tumor p53/genética
13.
Pathologe ; 33(2): 142-5, 2012 Mar.
Artigo em Alemão | MEDLINE | ID: mdl-22048329

RESUMO

A 76-year-old man presented clinically with coughing and shortness of breath and was diagnosed radiologically to have massive pleural effusion as a combined feature of yellow nail syndrome. A lung biopsy was taken and revealed histologically: chronic non-specific inflammation in the pleuropulmonary border, intrapleural edema with eightfold pleural thickening in comparison to normal, angiogenesis in both the nutritive and functional intrapleural blood vessels, no abnormalities of lymphatic vessels with normal topographical distribution as detected by immunohistochemistry for antibody D2-40, granulomatous chronic foreign body reaction as a consequence of pleural effusion therapy by talcum pleurodesis.The histopathological findings of chronic non-specific pleuritis with angiogenesis and increased permeability of blood vessels led to massive intrapleural edema with pleural effusion. Abnormalities of lymphatic vessels could not be confirmed. Considering the features of this disease, they are probably secondary to chronic r infectious or immunological inflammation or paraneoplastic complications with angiogenesis (in about 19%).


Assuntos
Pleurisia/patologia , Síndrome das Unhas Amareladas/patologia , Idoso , Biópsia , Tubos Torácicos , Diagnóstico Diferencial , Humanos , Pulmão/patologia , Vasos Linfáticos/patologia , Masculino , Neovascularização Patológica/patologia , Pleura/irrigação sanguínea , Pleura/patologia , Derrame Pleural/patologia , Pleurodese , Talco
14.
Pathologe ; 32(3): 220-7, 2011 May.
Artigo em Alemão | MEDLINE | ID: mdl-21505874

RESUMO

Menisci fulfill many functions within the complex biomechanics of the knee joint. In the case of meniscus lesions, sparing arthroscopic resection and surgical refixation are the treatments of choice. In terms of diagnosis, this means in general that histopathologic diagnostics are carried out on detached meniscus fragments of between 5 mm and 2 cm in size. A good knowledge of physiologically possible cellular and fibrous histological meniscus damage, as opposed to nonphysiological change regarded as normal with respect to age, is essential for diagnostic meniscus evaluation. The clinician expects clear statements from the pathologist regarding the severity of previous or secondary degenerative meniscus damage, the age and type of traumatic tears, and an appraisal of the relationship between trauma and meniscus damage from an insurance point of view. Close cooperation between the clinician and the pathologist allows for a fast and unambiguous correlation of anamnesis, the clinical picture, and morphological reporting such that problematic insurance cases can be clarified quickly.


Assuntos
Doenças das Cartilagens/patologia , Prova Pericial/legislação & jurisprudência , Meniscos Tibiais/patologia , Doenças Profissionais/patologia , Lesões do Menisco Tibial , Fatores Etários , Artroscopia , Doenças das Cartilagens/cirurgia , Diagnóstico Diferencial , Avaliação da Deficiência , Definição da Elegibilidade/legislação & jurisprudência , Alemanha , Humanos , Articulação do Joelho/patologia , Meniscos Tibiais/cirurgia , Doenças Profissionais/cirurgia , Osteoartrite/patologia , Osteocondrite/patologia , Fatores de Risco , Membrana Sinovial/patologia , Indenização aos Trabalhadores/legislação & jurisprudência
15.
Pathologe ; 32(2): 104-12, 2011 Mar.
Artigo em Alemão | MEDLINE | ID: mdl-21424408

RESUMO

Lung transplantation is the ultimate therapeutical approach for the treatment of both children and adults with terminal congenital or acquired lung disease. In contrast to survival rates during the first year following transplantation, the long-term survival for patients after lung transplantation has not significantly improved in the past. In addition to other complications, acute cellular rejection constitutes a major cause for diminished function of pulmonary grafts, and can, among other factors, be causative for chronic rejection (bronchiolitis obliterans syndrome, BOS). In 2006, the International Society for Heart and Lung Transplantation (ISHLT) provided a revised version of the grading system for acute and chronic rejection of pulmonary grafts.


Assuntos
Rejeição de Enxerto/patologia , Transplante de Pulmão/patologia , Adulto , Biópsia , Bronquiolite Obliterante/classificação , Bronquiolite Obliterante/imunologia , Bronquiolite Obliterante/mortalidade , Bronquiolite Obliterante/patologia , Criança , Rejeição de Enxerto/classificação , Rejeição de Enxerto/imunologia , Rejeição de Enxerto/mortalidade , Teste de Histocompatibilidade , Humanos , Imunidade Celular/imunologia , Imunossupressores/uso terapêutico , Leucócitos/imunologia , Leucócitos/patologia , Pulmão/imunologia , Pulmão/patologia , Transplante de Pulmão/imunologia , Prognóstico , Fatores de Risco , Taxa de Sobrevida , Imunologia de Transplantes/imunologia
16.
Eur J Neurol ; 18(2): 347-353, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20636371

RESUMO

BACKGROUND: Neuropsychiatric symptoms (NPS), mainly cognitive deficits up to dementia and depressive syndromes have been described repeatedly in Fabry disease (FD). However, examinations regarding the pattern, extent, and frequency of the NPS in FD are still lacking. Moreover, the relationship between NPS and brain structural alterations in FD is unknown. The aim of this study was 1) to characterize NPS in a relatively large cohort of adult subjects with FD, and 2) to explore the association of cognitive performance and depressive syndromes with the FD-typical brain structural findings. METHODS: Twenty-five Fabry patients (age 36.5 ± 11.0) with mild to moderate disease involvement and 20 age, gender-, and education-matched healthy controls were extensively studied by neuropsychiatric assessment, structural magnetic resonance imaging, magnetic resonance angiography, and diffusion-tensor imaging. RESULTS: Patients with FD showed deficits only in the attention domain. Clinically relevant depressive syndromes were noted in 60% of the patients. The subgroup of patients with markedly elevated volumes of white matter lesions (not associated with actual stroke; n=7) showed slightly more learning and memory deficits, but no higher depression rate compared to less affected patients. CONCLUSIONS: Against the prevailing assumption, Fabry patients, even those with marked brain structural alterations, showed only mild cognitive deficits. The high frequency of depression in FD is likely to be related to the burden of this chronic multiorganic hereditary disease, but not to the FD-typical brain structural alterations. Longitudinal studies are necessary to clear, if the mild cognitive deficits in FD might precede clinically relevant cognitive decline.


Assuntos
Encéfalo/patologia , Doença de Fabry/patologia , Doença de Fabry/psicologia , Adulto , Cognição/fisiologia , Transtornos Cognitivos/patologia , Depressão/etiologia , Depressão/patologia , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Testes Neuropsicológicos , Transtornos Psicóticos/etiologia , Transtornos Psicóticos/patologia
18.
Orthopade ; 38(6): 539-45, 2009 Jun.
Artigo em Alemão | MEDLINE | ID: mdl-19517096

RESUMO

Menisci fulfill many functions within the complex biomechanics of the knee joint. In the case of meniscus lesions, sparing arthroscopic resections and operative refixation are the treatments of choice. With regard to diagnostics, this means that in general terms, the histopathologic diagnostics are carried out on detached meniscus fragments of between 5 mm and 2 cm in size. An experienced pathologist's knowledge of physiologically possible cellular and fibrous histological meniscus damage, as opposed to nonphysiological change regarded as normal with respect to age, is essential during a diagnostic meniscus evaluation. The clinician expects clear statements from the pathologist regarding the severity of previous or secondary degenerative meniscus damage, the age and type of traumatic tears, and appraisal of the relationship between trauma and meniscus damage from an insurance point of view. Close cooperation between the clinician and the pathologist allows for fast and unambiguous correlation of anamnesis, the clinical picture, and morphological reporting so that cases involving insurance problems - which are numerous, often long-term, and often unsatisfactory - can be clarified quickly.


Assuntos
Doenças das Cartilagens/patologia , Fraturas de Cartilagem/patologia , Traumatismos do Joelho/patologia , Meniscos Tibiais/patologia , Lesões do Menisco Tibial , Humanos
19.
Neuroscience ; 161(2): 655-62, 2009 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-19345725

RESUMO

Aftereffects are perceptual illusions caused by visual adaptation to one or more stimulus attribute, such as orientation, motion, or shape. Neurophysiological studies seeking to understand the basis of visual adaptation have observed firing rate reduction and changes in tuning of stimulus-selective neurons following periods of prolonged visual stimulation. In the domain of shape, recent psychophysical work has shown that adaptation to a convex pattern induces a subsequently seen rectangle to appear slightly concave. In the present study, we investigate the possible contribution of V4 neurons of rhesus monkeys, which are thought to be involved in the coding of convexity, to shape-specific adaptation. Visually responsive neurons were monitored during the brief presentation of simple shapes varying in their convexity level. Each test presentation was preceded by either a blank period or several seconds of adaptation to a convex or concave stimulus, presented in two different sizes. Adaptation consistently shifted the tuning of neurons away from the convex or concave adapter, including shifting response to the neutral rectangle in the direction of the opposite convexity. This repulsive shift resembled the known perceptual distortion associated with adaptation to such stimuli. In addition, adaptation caused a nonspecific response decrease, as well as a specific decrease for repeated stimuli. The latter effects were observed whether or not the adapting and test stimuli matched closely in their size. Taken together, these results provide evidence for shape-specific adaptation of neurons in area V4, which may contribute to the perception of the convexity aftereffect.


Assuntos
Percepção de Forma , Córtex Visual/fisiologia , Animais , Mapeamento Encefálico , Macaca mulatta , Masculino , Neurônios/fisiologia , Estimulação Luminosa
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA