Foci of orientation plasticity in visual cortex

[Abstract] Cortical areas are generally assumed to be uniform in their capacity for adaptive changes or plasticity1, 2, 3, 4. Here we demonstrate, however, that neurons in the cat striate cortex (V1) show pronounced adaptation-induced short-term plasticity of orientation tuning primarily at specific foci. V1 neurons are clustered according to their orientation preference in iso-orientation domains5 that converge at singularities or pinwheel centres6, 7. Although neurons in pinwheel centres have similar orientation tuning and responses to those in iso-orientation domains, we find that they differ markedly in their capacity for adaptive changes. Adaptation with an oriented drifting grating stimulus alters responses of neurons located at and near pinwheel centres to a broad range of orientations, causing repulsive shifts in orientation preference and changes in response magnitude. In contrast, neurons located in iso-orientation domains show minimal changes in their tuning properties after adaptation. The anisotropy of adaptation-induced orientation plasticity is probably mediated by inhomogeneities in local intracortical interactions that are overlaid on the map of orientation preference in V1

A Meta-Analysis and Genome-Wide Association Study of Platelet Count and Mean Platelet Volume in African Americans

Several genetic variants associated with platelet count and mean platelet volume (MPV) were recently reported in people of European ancestry. In this meta-analysis of 7 genome-wide association studies (GWAS) enrolling African Americans, our aim was to identify novel genetic variants associated with platelet count and MPV. For all cohorts, GWAS analysis was performed using additive models after adjusting for age, sex, and population stratification. For both platelet phenotypes, meta-analyses were conducted using inverse-variance weighted fixed-effect models. Platelet aggregation assays in whole blood were performed in the participants of the GeneSTAR cohort. Genetic variants in ten independent regions were associated with platelet count (N = 16,388) with p<5×10−8 of which 5 have not been associated with platelet count in previous GWAS. The novel genetic variants associated with platelet count were in the following regions (the most significant SNP, closest gene, and p-value): 6p22 (rs12526480, LRRC16A, p = 9.1×10−9), 7q11 (rs13236689, CD36, p = 2.8×10−9), 10q21 (rs7896518, JMJD1C, p = 2.3×10−12), 11q13 (rs477895, BAD, p = 4.9×10−8), and 20q13 (rs151361, SLMO2, p = 9.4×10−9). Three of these loci (10q21, 11q13, and 20q13) were replicated in European Americans (N = 14,909) and one (11q13) in Hispanic Americans (N = 3,462). For MPV (N = 4,531), genetic variants in 3 regions were significant at p<5×10−8, two of which were also associated with platelet count. Previously reported regions that were also significant in this study were 6p21, 6q23, 7q22, 12q24, and 19p13 for platelet count and 7q22, 17q11, and 19p13 for MPV. The most significant SNP in 1 region was also associated with ADP-induced maximal platelet aggregation in whole blood (12q24). Thus through a meta-analysis of GWAS enrolling African Americans, we have identified 5 novel regions associated with platelet count of which 3 were replicated in other ethnic groups. In addition, we also found one region associated with platelet aggregation that may play a potential role in atherothrombosis

Rede de frio para a conservação de vacinas em unidades públicas do município de São Paulo: conhecimento e prática Vaccine storage cold chain in public health units of the City of São Paulo: knowledge and practice

Para assegurar a eficácia das vacinas utilizadas no Programa de Imunização é fundamental a manutenção da rede de frio. Este estudo tem o objetivo de avaliar o conhecimento e a prática adotados na conservação das vacinas nas unidades públicas do município de São Paulo. Foram enviados formulários a 390 salas com atividades de rotina e 80 foram selecionadas para uma entrevista com um profissional e observação do refrigerador. Um indicador foi construído para sintetizar os resultados, mediante a atribuição de pontos a itens comuns dos instrumentos utilizados, estabelecendo-se a classificação arbitrária de conhecimento/cumprimento SUFICIENTE, REGULAR e INSUFICIENTE. Sessenta por cento das unidades responderam o formulário, 80 salas foram visitadas e 90 refrigeradores foram observados. Resultados SUFICIENTES foram obtidos por 66% das observações, 55% das entrevistas e 53% dos formulários. O treinamento em sala de vacina influenciou positivamente a maior pontuação das observações. A concordância entre os instrumentos foi baixa, proporcionando a reflexão sobre a maneira como as informações da conservação de vacinas são transmitidas e a necessidade da supervisão sistemática para correção das falhas detectadas.<br>The cold chain is essential to assure the efficacy of the vaccines used in immunization programs. This study aimed to assess the knowledge and the practice adopted in vaccine storage in public units of the city of São Paulo. Forms were sent to 390 health units with custom activities, and 80 were selected for a visit and an interview with a health worker and for observation of the refrigerator. An indicator was built to summarize results, and scores were given to common items of the tools utilized, establishing an arbitrary classification of SUFFICIENT, REGULAR and INSUFFICIENT knowledge/accomplishment. Sixty percent of the units answered the form, all the selected units were visited, and 90 refrigerators were observed. SUFFICIENT results were achieved by 66% observations, 55% interviews, and 53% formularies. Training in vaccine units influenced positively higher scores in observations. Agreement among tools was low, leading to considerations on the way in which vaccines storage guidelines are conveyed, along with the need for systematic supervision to correct the faults detected