Movimientos visuales y desempeño deportivo del tenista: revisión de alcance / Visual Movements and Sports Performance of the Tennis Player: Scoping Review / Movimentos visuais e desempenho esportivo do tenista: Revisão do escopo

Resumen Propósito: El presente estudio tiene como objetivo explorar la bibliografía existente sobre las habilidades y movimientos visuales en jugadores de tenis. Metodología: Se indagó en las bases de datos Scopus, SPORTDiscus, PubMed y Google Scholar que permn seleccionar 37 estudios empíricos realizados con un método cuantitativo. La elección de los estudios respondió a los criterios establecidos en torno a las palabras clave, temática del estudio y la metodología de investigación. Resultados: Los resultados se organizan en tres tópicos centrales: (a) Antecedentes de habilidades visuales en el siglo XX, (b) Siglo XXI: rol de los movimientos sacádicos y (c) Reflexiones sobre la gesta tenística y los movimientos sacádicos. Conclusiones: A lo largo de varias décadas de investigación y seguimiento al enfoque ''visión y deporte'' en el tenis de campo, específicamente en los movimientos visuales entre fijaciones y movimientos sacádicos, se pueden identificar niveles diferenciales de rendimiento tenístico con el potencial de ser indicadores de mejores desempeños deportivos. Dado que las herramientas utilizadas hasta ahora en esta disciplina para los procesos de selección o evaluación no son determinantes, debido a ser una disciplina deportiva multifactorial de orden perceptivo-motor y de habilidades abiertas, se sugiere que las habilidades visuales pueden ser indispensables para la adquisición de un alto nivel competitivo. Este aspecto plantea una línea de investigación interesante que merece una mayor exploración en el futuro.

Abstract: Purpose: The presente study aims to explore the existing bibliography on visual skills and visual movements in tennis players. Method: We searched the Scopus, SPORTDiscus, PubMed and Google Scholar databases, which allowed us to select 37 empirical studies carried out with a quantitative method. The choice of the studies responded to the criteria established around the Keywords, the subject of the study and the research methodology. Results: The results are organized into three central topics: (a) Antecedents of visual skills in the 20th century, (b) 21st century: Role of saccadic movements, and (c) Reflections on the tennis feat and saccadic movements. Conclusions: Throughout several decades of research and monitoring of the ''vision and sport'' approach in field tennis, specifically in the visual movements between fixations and saccadic movements, differential levels of tennis performance can be identified with the potential to be indicators of better sports performance. Given that the tools used so far in this discipline for the selection and/or evaluation processes are not determinant, due to being a multifactorial sport discipline of perceptual-motor order and open skills, it is suggested that visual skills may be essential for the acquisition of a high competitive level. This aspect raises an interesting line of research that deserves further exploration in the future.

Resumo: Propósito: O presente estudo tem como objetivo explorar a literatura existente sobre habilidades e movimentos visuais em jogadores de tênis. Metodologia: Pesquisamos os bancos de dados Scopus, SPORTDiscus, PubMed e Google Scholar, o que nos permitiu selecionar 37 estudos empíricos realizados com um método quantitativo. A escolha dos estudos atendeu aos critérios estabelecidos em torno das palavras-chave, do tema do estudo e da metodologia da pesquisa. Resultados: Os resultados estão organizados em três tópicos centrais: (a) Precedentes das habilidades visuais no século XX, (b) Século XXI: Papel dos movimentos sacádicos (c) Reflexões sobre a proeza do tênis e os movimentos sacádicos. Conclusões: Ao longo de várias décadas de pesquisa e monitoramento da abordagem ''visão e esporte'' no tênis de campo, especificamente nos movimentos visuais entre fixações e movimentos sacádicos, podem ser identificados níveis diferenciais de desempenho no tênis com potencial para serem indicadores de melhores desempenhos esportivos. Considerando que as ferramentas utilizadas até o momento nessa modalidade para os processos de seleção e/ou avaliação não são determinantes, devido ao fato de ser uma modalidade esportiva multifatorial de ordem perceptivomotora e de habilidades abertas, sugere-se que as habilidades visuais podem ser essenciais para a aquisição de um alto nível competitivo. Esse aspecto levanta uma linha de pesquisa interessante que merece ser mais explorada no futuro.

Investigating Morphological Changes of the Hippocampus After Prolonged Aerobic Exercise in Mice: Neural Function and Learning Capabilities / Investigación de los Cambios Morfológicos del Hipocampo Después De un Ejercicio Aeróbico Prolongado en Ratones: Función Neuronal y Capacidades de Aprendizaje

SUMMARY: Both the academic and popular worlds have paid close attention to the link between exercise and cognitive performance. It is increasingly important to understand the numerous mechanisms by which exercise might influence cognitive abilities in view of the continuous societal issues caused by aging populations and the prevalence of disorders associated to cognitive decline. A rising amount of evidence showing a favorable association between physical activity and cognitive well-being serves as the foundation for the justification for studying the effects of exercise on cognitive function and learning ability. The study employed an 8-week treadmill based on exercise on male adults C57BL/6 mice. The exercise group were engaged in 5 sessions a week gradually increasing the intensity of the protocol by 5 % each week. The Mice cognitive assessments were done using Morris Water Maze and Novel Object Recognition tests. The long term-impact on learning ability were further assessed through immmohistochemistry and molecular analysis of the hippocampal and prefrontal cortex tissues of the animals' brain tissues. The findings showed improved spatial learning abilities, recognition memory, and heighted synaptic plasticity indicated by elevated synaptic makers. The study underscores the role of long-term aerobic exercise in augmenting cognitive performance. It not only contributes to the understanding of the interplay between neuroplasticity and cognitive benefits but also the growing body of research on the impact of exercise on cognitive function.

Tanto el mundo académico como el popular han prestado mucha atención al vínculo entre el ejercicio y el rendimiento cognitivo. Es cada vez más importante comprender los numerosos mecanismos por los cuales el ejercicio podría influir en las capacidades cognitivas en vista de los continuos problemas sociales causados por el envejecimiento de la población y la prevalencia de trastornos asociados al deterioro cognitivo. Una cantidad cada vez mayor de evidencia que muestra una asociación favorable entre la actividad física y el bienestar cognitivo sirve como base para justificar el estudio de los efectos del ejercicio sobre la función cognitiva y la capacidad de aprendizaje. El estudio se realizó en ratones machos adultos C57BL/6 utilizándose en los ejercicios una cinta rodante durante 8 semanas. El grupo de ejercicio realizó 5 sesiones por semana aumentando gradualmente la intensidad del protocolo en un 5 % cada semana. Las evaluaciones cognitivas de los ratones se realizaron utilizando las pruebas Morris Water Maze y Novel Object Recognition. El impacto a largo plazo en la capacidad de aprendizaje se evaluó mediante inmunohistoquímica y análisis molecular de los tejidos del hipocampo y la corteza prefrontal de los tejidos cerebrales de los animales. Los hallazgos mostraron mejoras en las habilidades de aprendizaje espacial, la memoria de reconocimiento y una mayor plasticidad sináptica indicada por unos creadores sinápticos elevados. El estudio subraya el papel del ejercicio aeróbico a largo plazo para aumentar el rendimiento cognitivo. No sólo contribuye a la comprensión de la interacción entre la neuroplasticidad y los beneficios cognitivos, sino también al creciente conjunto de investigaciones sobre el impacto del ejercicio en la función cognitiva.

Relação entre meditação, regulação emocional e expressão vocal: estudo de intervenção / Relación entre meditación, regulación emocional y expresión vocal: estudio de intervención / The relationship between meditation, emotional regulation and vocal expression: interventional study

Introdução: A voz é um indicador de estados emocionais, influenciada por fatores como o tônus vagal, a respiração e a variabilidade da frequência cardíaca. O estudo explora esses fatores e a relação com a regulação emocional e a prática meditativa como técnica de autorregulação. Objetivo: Investigar a diferença nas características vocais e na variação da frequência cardíaca em meditadores experientes (EM) e novatos (NM) antes e depois de uma prática meditativa e em não praticantes de meditação ­ grupo controle (CG), antes e depois de um teste controle. Métodos: Estudo quase-fatorial 3 x 2. Três grupos foram avaliados (meditadores experientes EM; meditadores novatos NM; e grupo controle CG, não praticantes de meditação) em dois momentos da manipulação experimental ­ antes e depois de uma sessão meditativa para praticantes de meditação, e antes e depois de uma tarefa de busca de palavras para o grupo controle. A frequência fundamental, jitter, shimmer, relação harmônico-ruído e o primeiro (F1), o segundo (F2) e terceiro (F3) formantes da vogal [a]; a variação da frequência cardíaca (SDNN, RMSSD, LF/HF, SD1 and SD2); estado de ansiedade e autopercepção vocal, foram investigados, antes e após a intervenção. Resultados: O grupo EM alcançou ótimo relaxamento do trato vocal. Os grupos NM e CG apresentaram mudanças em F1. Prática meditativa, de longa duração, está associado com grande diferença em F3, SDNN e SD2 na variação da frequência cardíaca. Conclusão: Os resultados sugerem que prática meditativa influencia a expressão vocal e reação emocional, e que a experiência em prática meditativa favorece esta relação. (AU)

Introduction: The voice is an indicator of emotional states, influenced by factors such as vagal tone, breathing and heart rate variability. This study explores these factors and their relationship with emotional regulation and meditative practice as a self-regulation technique. Purpose: To investigate the difference in vocal characteristics and heart rate variability in experienced (EM) and novice (NM) meditators before and after a meditation practice and in non-meditators - control group (CG), before and after a control test. Methods: 3 x 2 quasi-factorial study. Three groups were evaluated (experienced meditators EM; novice meditators NM; and control group CG, non-meditators) at two points in the experimental manipulation - before and after a meditation session for meditators, and before and after a word search task for the control group. The fundamental frequency, jitter, shimmer, harmonic-to-noise ratio and the first (F1), second (F2) and third (F3) formants of the vowel [a]; heart rate variation (SDNN, RMSSD, LF/HF, SD1 and SD2); anxiety state and vocal self-perception, were investigated, before and after the intervention. Results: The EM group achieved optimal vocal tract relaxation. The NM and CG groups showed changes in F1. Long-term meditative practice was associated with a large difference in F3, SDNN and SD2 in heart rate variation. Conclusion: The results suggest that meditation practice influences vocal expression and emotional reaction, and that experience in meditation practice favors this relationship. (AU)

Introducción: La voz es un indicador de los estados emocionales, influida por factores como el tono vagal, la respiración y la variabilidad de la frecuencia cardiaca. Este estudio explora estos factores y su relación con la regulación emocional y la práctica de la meditación. Objetivo: Investigar la diferencia en las características vocales y variabilidad de la frecuencia cardiaca en meditadores experimentados (EM) y novatos (NM) antes y después de una práctica de meditación y en no meditadores - grupo control (GC), antes y después de una prueba control. Métodos: Estudio cuasi-factorial 3 x 2. Se evaluaron tres grupos (meditadores experimentados EM; meditadores novatos NM; y grupo control CG, no meditadores) en dos momentos - antes y después de una sesión de meditación para los meditadores, y antes y después de una tarea de búsqueda de palabras para el grupo control. Se investigaron la frecuencia fundamental, jitter, shimmer, relación armónico-ruido y los formantes primero (F1), segundo (F2) y tercero (F3) de la vocal [a]; la variación de la frecuencia cardiaca (SDNN, RMSSD, LF/HF, SD1 y SD2); el estado de ansiedad y autopercepción vocal, antes y después de la intervención. Resultados: El grupo EM consiguió una relajación óptima del tracto vocal. Los grupos NM y CG mostraron cambios en F1. La práctica de meditación a largo plazo se asocia con una gran diferencia en F3, SDNN y SD2 en la variación de la frecuencia cardiaca. Conclusión: Los resultados sugieren que la práctica de meditación influye en la expresión vocal y reacción emocional. (AU)

Anthropometric Characteristics, Training Intensity Distribution, Physiological Profile and Performance of an Elite Trail Runner: A Longitudinal Case Study / Características Antropométricas, Distribución de la Intensidad del Entrenamiento, Perfil Fisiológico y Rendimiento de un Corredor de Montaña de Élite: Un Estudio de Caso Longitudinal

SUMMARY: Trail running (TR), an extreme endurance sport, presents unique challenges due to the variety of terrain and distances, where physiological capacity and body composition have been considered better predictors of performance. This longitudinal case study examines the impact of training intensity distribution (TID) on an elite trail runner's physiological profile and performance over four years. Two TID models were implemented: polarized (POL) and pyramidal (PYR). Physiological assessments included maximal oxygen consumption (VO2max), lactate thresholds (LT1 and LT2), and anthropometric characteristics. The training was classified according to the 3-zone intensity model (zone 1: below the first lactate threshold; zone 2: between the first and second lactate threshold; zone 3: above the second lactate threshold). During the four years, the average TID distribution was 75 % zone 1, 18 % zone 2, and 7 % zone 3. Physiological capacity increased by 7.14 % (14 to 15 km/h) for velocity at LT1 (vLT1) and 8.13 % (16 to 17.3 km/h) for velocity at LT2 (vLT2). The most significant increases were observed during the second year when the percentage of training time in zone 1 was lower (65 %) and in zone 2 greater (30 %) than those reported in other years. Consequently, vLT1 and vLT2 increased by 3.5 % (from 14.1 to 14.6 km/h) and 3.6 % (from 16.5 to 17.1 km/h), respectively. In conclusion, this case study revealed that emphasizing training in zone 2 (moderate intensity) and increasing the training load significantly improved performance at lactate thresholds. Despite modifying body composition, no influence on improving endurance performance was observed. These findings underscore the importance of TID in elite trail runners and highlight the potential to optimize physiological adaptations and performance outcomes.

Trail running (TR), un deporte de resistencia extrema, presenta desafíos únicos debido a la variedad de terrenos y distancias, donde la capacidad fisiológica y la composición corporal se han considerado mejores predictores del rendimiento. Este estudio de caso longitudinal examina el impacto de la distribución de la intensidad del entrenamiento (TID) en el perfil fisiológico y el rendimiento de un corredor de montaña de élite durante cuatro años. Se implementaron dos modelos TID: polarizado (POL) y piramidal (PYR). Las evaluaciones fisiológicas incluyeron el consumo máximo de oxígeno (VO2max), los umbrales de lactato (LT1 y LT2) y las características antropométricas. El entrenamiento se clasificó según el modelo de intensidad de 3 zonas (zona 1: por debajo del primer umbral de lactato; zona 2: entre el primer y segundo umbral de lactato; zona 3: por encima del segundo umbral de lactato). Durante los cuatro años, la distribución TID promedio fue 75 % zona 1, 18 % zona 2 y 7 % zona 3. La capacidad fisiológica aumentó un 7,14 % (14 a 15 km/h) para la velocidad en LT1 (vLT1) y un 8,13 % (16 a 17,3 km/h) para velocidad en LT2 (vLT2). Los incrementos más significativos se observaron durante el segundo año cuando el porcentaje de tiempo de entrenamiento en la zona 1 fue menor (65 %) y en la zona 2 mayor (30 %) que los reportados en otros años. En consecuencia, vLT1 y vLT2 aumentaron un 3,5 % (de 14,1 a 14,6 km/h) y un 3,6 % (de 16,5 a 17,1 km/h), respectivamente. En conclusión, este estudio reveló que enfatizar el entrenamiento en la zona 2 (intensidad moderada) y aumentar la carga de entrenamiento mejoró significativamente el rendimiento en los umbrales de lactato. A pesar de modificar la composición corporal, no se observó influencia en la mejora del rendimiento de resistencia. Estos hallazgos subrayan la importancia del TID en los corredores de trail de élite y resaltan el potencial para optimizar las adaptaciones fisiológicas y los resultados de rendimiento.

Importancia biológica de los telómeros / Biological importance of telomeres

Se exponen los hallazgos históricos y la importancia biológica de los telómeros en la vida celular y en los aspectos genéticos del ADN humano. (AU)

The discovery and the biological importance of the telomeres are exposed. (AU)

El reposicionamiento malar. Presentación de una técnica original: punto MM / Malar repositioning. Presentation of an original technique: point MM

El envejecimiento facial es una sinergia compleja de cambios texturales de la piel, hiper- o hipoactividad muscular, reabsorción del tejido graso y resorción ósea. El déficit de volumen resultante, la deflación y la posterior caída del tercio medio facial produce una cara menos atractiva y juvenil. Los procedimientos inyectables en región malar son cada vez más populares y solicitados por los pacientes. El conocimiento de la anatomía de la cara media es fundamental para el inyector. La comprensión de la irrigación facial puede ayudar a disminuir la exposición a la aparición de hematomas y complicaciones vasculares severas. Existen múltiples técnicas de inyección propuestas para el tercio medio, en este artículo presentamos una técnica original, simple, segura y eficaz con resultados satisfactorios y riesgo reducido

Facial aging is a complex synergy of textural skin changes, muscle hyperactivity, fat dysmorphism, bone resorption. The resulting volume deficit and deflation of the mid face produces a less attractive and youthful face. Injectable midface procedures are becoming increasingly popular and requested by patients. Knowledge of the anatomy of the midface is critical for the injector. Understanding the irrigation of the face can help decrease the risk of hematoma and severe vascular complications. There are multiple injection techniques proposed for the middle third, in this article we present a simple, safe and effective technique with satisfactory results and lower risk

Rejuvenecimiento periorbitario fisiológico / Physiological periorbital rejuvenation

Pivoting Brow Lift es una nueva opción terapéutica cuyas ventajas son tres mínimas incisiones, prácticamente imperceptibles, bien aceptadas por pacientes de todas las edades, sexo y incluso pacientes calvos. Una incisión se realiza en la región temporal y otra dentro del cuero cabelludo en la región medio frontal o en una arruga en pacientes calvos. La disección en región frontal es sub-perióstica, muchas veces llega a la punta nasal para reposicionarla. La disección en la región temporal se realiza entre las hojas superficiales y profundas extendiéndose hasta el tarso y canto externo del ojo; en la región palpebral la disección se realiza entre la piel y el musculo. La fijación son dos puntos externos en el cuero cabelludo y unos papeles adherentes. Los puntos del cuero cabelludo se retiran a los 14 días. Evita las complejas fijaciones que se realizan actualmente con tornillos, puntos internos o Endotime. La sencillez del procedimiento hace que este se pueda realizar entre 30 y 45 minutos, con anestesia local y sedación; esto permite lograr una mayor seguridad operatoria. Se han documentado pacientes tratados hace 9 años donde se demuestra la duración en el tiempo. El bajo índice de complicaciones y la alta satisfacción de los pacientes documentadas en encuestas hace que este procedimiento pueda ser considerado como una nueva opción terapéutica.

Desarrollo embriológico e importancia clínica de la membrana amniótica: revisión narrativa de literatura / Embryological development and clinical significance of the amniotic membrane: narrative literature review

La membrana amniótica (MA), ubicada en el lado interno de la placenta fetal, ha sido objeto de múltiples investigaciones para intentar dilucidar su papel embriológico y su potencial celular terapéutico. Actualmente las limitaciones del estudio en fetos humanos hacen que parte de su funcionamiento sea una incógnita, sin embargo algunos estudios clínicos y básicos nos dan luz sobre su papel en la médica moderna. Se realizó una revisión bibliográfica de la literatura desde 1960 hasta 2022, empleando bases de datos como PubMed, SciELO y Scopus, siendo incluidos un total de 50 artículos y dos textos de embriología. El objetivo de esta revisión narrativa fue sintetizar la información sobre la angiogénesis y su importancia clínica. La información recopilada permitió evidenciar que las propiedades de curación de la piel del feto se deben a factores intrínsecos del feto, y a que las células epiteliales amnióticas humanas poseen una diferenciación similar a las células madre embrionarias, con la capacidad de diferenciación similar al de las células mesenquimales, resaltando su importancia clínica por sus características regenerativas. En conclusión, el desarrollo embrionario humano sigue siendo relativamente inexplicable, pero su conocimiento ha permitido grandes avances, que podrían ser útiles en terapias de regeneración, reparación de tejidos y órganos lesionados.

The amniotic membrane, located on the inner side of the fetal placenta, has been the subject of multiple investigations to try to elucidate its embryological role and its therapeutic cellular potential. Currently, the limitations of the study in human fetuses mean that part of its functioning is unknown, however, some clinical and basic studies shed light on its role in modern medicine. A bibliographic review of the literature was carried out from 1960 to 2022, using databases such as PubMed, SciELO and Scopus, including a total of 50 articles and two embryology texts. The objective of this narrative review was to synthesize information on angiogenesis and its clinical importance. The information collected made it possible to show that the healing properties of the fetal skin are due to intrinsic factors of the fetus, and that human amniotic epithelial cells have a differentiation similar to embryonic stem cells, with the differentiation capacity similar to that of mesenchymal cells, highlighting their clinical importance due to their regenerative characteristics. In conclusion, human embryonic development remains relatively inexplicable, but its knowledge has allowed great advances, which could be useful in regeneration therapies, repair of injured tissues and organs.

Hipertensión arterial sistémica posterior a COVID-19 / Systemic arterial hypertension after COVID-19

Introducción: un nuevo tipo de coronavirus que se nombró SARSCoV-2, responsable de la enfermedad por COVID-19, tuvo esparcimiento rápido en el mundo, por alta transmisión que resultó en pandemia. Se registraron 2'397,216 casos confirmados, con 162,956 defunciones en el mundo, de acuerdo con la Organización Mundial de la Salud (OMS), en abril de 2020. Sin embargo, la hipertensión afecta a 40% de adultos, lo que significa que alrededor de 250 millones de personas padecen de presión alta. La OMS, de acuerdo con sus reportes, refiere que la hipertensión es el factor de riesgo número uno de muerte. Uno de cada cuatro mexicanos padece hipertensión arterial. Objetivos: establecer la incidencia de la hipertensión arterial sistémica posterior a padecer COVID-19 en pacientes de la Unidad de Medicina Familiar (UMF) No. 48. Material y métodos: es un estudio transversal, observacional y descriptivo, conformado por 3,238 pacientes con diagnóstico de COVID-19 positivo, de ambos sexos, con edades entre 18 y 70 años. Por medio de la fórmula para poblaciones infinitas se obtiene una muestra de 348 pacientes. Se realizó revisión de expedientes en el Sistema de Información de Medicina Familiar, versión 6.2, para obtención de la información correspondiente. Resultados: 27 pacientes diagnosticados con hipertensión arterial posterior al diagnóstico de COVID-19, 52% del sexo masculino y 48% del femenino, con media de edad de 39 años, 74% correspondió a enfermedad leve por COVID-19 y 26% a enfermedad moderada. Se documenta mediana de ocho días por periodo de infección por COVID-19. En el círculo femenino el promedio de la aparición de hipertensión arterial fue de 13 meses y en el masculino la media de desarrollo de hipertensión arterial posterior a COVID-19 fue de seis meses (AU)

Introduction: a new type of coronavirus that was named SARSCoV-2, responsible for the COVID-19 disease, with rapid spread in the world, due to high transmission that resulted in pandemic. There were 2'397,216 confirmed cases, with 162,956 deaths in the world, according to the WHO in April 2020. However, hypertension affects 40% of adults and means that around 250 million people suffer from high blood pressure. The WHO, according to its reports, refers that hypertension is the number one risk factor for death. One in four Mexicans suffers from high blood pressure. Objectives: to establish the incidence of systemic arterial hypertension after suffering from COVID-19 in patients of the UMF No. 48. Material and methods: it is a cross-sectional, observational and descriptive study, consisting of 3,238 patients with a positive COVID-19 diagnosis of both sexes, aged 18-70 years. Through the formula for infinite populations a sample of 348 patients is obtained. Will proceed with review of files in the Family Medicine Information System, version 6.2, to obtain the corresponding information. Results: 27 patients diagnosed with hypertension after the diagnosis of COVID-19, 52% of the male sex and 48% of the female sex, with a mean age of 39 years; 74% corresponds to a mild illness by COVID-19 and 26% to moderate disease. A median of 8 days per period of infection by COVID-19 is documented. In the female circle, the average onset of hypertension was 13 months and as for the male sex, the mean development of hypertension after COVID-19 was six months (AU)

What triggers phenological events in plants under seasonal environments? A study with phylogenetically related plant species in sympatry / O que desencadeia eventos fenológicos em plantas em ambientes sazonais? Um estudo com espécies de plantas filogeneticamente relacionadas e em simpatria

In this study, we evaluated variation in vegetative and reproductive phenological events of four phylogenetically related plant species subjected to a seasonal environment. To this aim, we sampled 15 individuals of each plant species every fortnight for one year, between January and December of 2017. To assess when a given phenophase occurred more intensely in the population, the Fournier intensity index was used and the synchrony of individuals of the sample in a given phenological event was estimated using the activity index. The Rayleigh (Z) test was used to determine whether the phenological events have seasonal distribution. The relationship of abiotic factors (photoperiod, precipitation, relative humidity and temperature) with the intensity of phenophases was evaluated for each plant species using generalized linear models (GLMs). The phenophases of all plants showed a seasonal distribution pattern, as well as variation in synchrony of phenophases and specific sets of abiotic factors significantly influenced their phenophases. New leaves, for example, were produced throughout the seasons, with intense leaf fall in the dry season. Flowering periods, on the other hand, did not overlap. Indeed, species exhibited sequential flowering and asynchronous flowering among individuals. Our results suggest that the phenological patterns of four sympatric plant species are directly linked to climatic variables, but different abiotic factors affected different phenophases.

Neste estudo, avaliamos a variação nos eventos fenológicos vegetativos e reprodutivos de quatro espécies de plantas filogeneticamente relacionadas submetidas a um ambiente sazonal. Para isso, amostramos 15 indivíduos de cada espécie quinzenalmente, pelo período de um ano, entre janeiro e dezembro de 2017. Para avaliar quando uma determinada fenofase ocorreu de modo mais intenso na população foi utilizado o índice de intensidade de Fournier e a sincronia dos indivíduos da amostra em determinado evento fenológico foi estimada utilizando-se o índice de atividade. O teste de Rayleigh (Z) foi usado para determinar se os eventos fenológicos têm distribuição sazonal. A relação dos fatores abióticos (fotoperíodo, precipitação, temperatura e umidade relativa) com a intensidade das fenofases foi avaliada para cada espécie de planta usando modelos lineares generalizados (GLMs). As fenofases de todas as plantas apresentaram um padrão de distribuição sazonal, bem como variação na sincronia das fenofases e conjuntos específicos de fatores abióticos influenciaram significativamente suas fenofases. Folhas novas, por exemplo, foram produzidas ao longo das estações, com intensa queda de folhas na estação seca. Os períodos de floração, por outro lado, não se sobrepuseram. De fato, as espécies exibiram floração sequencial e floração assíncrona entre os indivíduos. Nossos resultados sugerem que os padrões fenológicos das quatro espécies de plantas simpátricas estão diretamente ligados às variáveis climáticas, mas diferentes fatores abióticos afetaram diferentes fenofases.

Distributions of Visual Receptive Fields from Retinotopic to Craniotopic Coordinates in the Lateral Intraparietal Area and Frontal Eye Fields of the Macaque / 神经科学通报·英文版

Even though retinal images of objects change their locations following each eye movement, we perceive a stable and continuous world. One possible mechanism by which the brain achieves such visual stability is to construct a craniotopic coordinate by integrating retinal and extraretinal information. There have been several proposals on how this may be done, including eye-position modulation (gain fields) of retinotopic receptive fields (RFs) and craniotopic RFs. In the present study, we investigated coordinate systems used by RFs in the lateral intraparietal (LIP) cortex and frontal eye fields (FEF) and compared the two areas. We mapped the two-dimensional RFs of neurons in detail under two eye fixations and analyzed how the RF of a given neuron changes with eye position to determine its coordinate representation. The same recording and analysis procedures were applied to the two brain areas. We found that, in both areas, RFs were distributed from retinotopic to craniotopic representations. There was no significant difference between the distributions in the LIP and FEF. Only a small fraction of neurons was fully craniotopic, whereas most neurons were between the retinotopic and craniotopic representations. The distributions were strongly biased toward the retinotopic side but with significant craniotopic shifts. These results suggest that there is only weak evidence for craniotopic RFs in the LIP and FEF, and that transformation from retinotopic to craniotopic coordinates in these areas must rely on other factors such as gain fields.

Neuronomodulation of Excitable Neurons / 神经科学通报·英文版

Neuronomodulation refers to the modulation of neural conduction and synaptic transmission (i.e., the conduction process involved in synaptic transmission) of excitable neurons via changes in the membrane potential in response to chemical substances, from spillover neurotransmitters to paracrine or endocrine hormones circulating in the blood. Neuronomodulation can be direct or indirect, depending on the transduction pathways from the ligand binding site to the ion pore, either on the same molecule, i.e. the ion channel, or through an intermediate step on different molecules. The major players in direct neuronomodulation are ligand-gated or voltage-gated ion channels. The key process of direct neuronomodulation is the binding and chemoactivation of ligand-gated or voltage-gated ion channels, either orthosterically or allosterically, by various ligands. Indirect neuronomodulation involves metabotropic receptor-mediated slow potentials, where steroid hormones, cytokines, and chemokines can implement these actions. Elucidating neuronomodulation is of great significance for understanding the physiological mechanisms of brain function, and the occurrence and treatment of diseases.

Temporal Unfolding of Racial Ingroup Bias in Neural Responses to Perceived Dynamic Pain in Others / 神经科学通报·英文版

In this study, we investigated how empathic neural responses unfold over time in different empathy networks when viewing same-race and other-race individuals in dynamic painful conditions. We recorded magnetoencephalography signals from Chinese adults when viewing video clips showing a dynamic painful (or non-painful) stimulation to Asian and White models' faces to trigger painful (or neutral) expressions. We found that perceived dynamic pain in Asian models modulated neural activities in the visual cortex at 100 ms-200 ms, in the orbitofrontal and subgenual anterior cingulate cortices at 150 ms-200 ms, in the anterior cingulate cortex around 250 ms-350 ms, and in the temporoparietal junction and middle temporal gyrus around 600 ms after video onset. Perceived dynamic pain in White models modulated activities in the visual, anterior cingulate, and primary sensory cortices after 500 ms. Our findings unraveled earlier dynamic activities in multiple neural circuits in response to same-race (vs other-race) individuals in dynamic painful situations.

Single-Cell Mapping of Brain Myeloid Cell Subsets Reveals Key Transcriptomic Changes Favoring Neuroplasticity after Ischemic Stroke / 神经科学通报·英文版

Interactions between brain-resident and peripheral infiltrated immune cells are thought to contribute to neuroplasticity after cerebral ischemia. However, conventional bulk sequencing makes it challenging to depict this complex immune network. Using single-cell RNA sequencing, we mapped compositional and transcriptional features of peri-infarct immune cells. Microglia were the predominant cell type in the peri-infarct region, displaying a more diverse activation pattern than the typical pro- and anti-inflammatory state, with axon tract-associated microglia (ATMs) being associated with neuronal regeneration. Trajectory inference suggested that infiltrated monocyte-derived macrophages (MDMs) exhibited a gradual fate trajectory transition to activated MDMs. Inter-cellular crosstalk between MDMs and microglia orchestrated anti-inflammatory and repair-promoting microglia phenotypes and promoted post-stroke neurogenesis, with SOX2 and related Akt/CREB signaling as the underlying mechanisms. This description of the brain's immune landscape and its relationship with neurogenesis provides new insight into promoting neural repair by regulating neuroinflammatory responses.

Stem Cell-Based Hair Cell Regeneration and Therapy in the Inner Ear / 神经科学通报·英文版

Hearing loss has become increasingly prevalent and causes considerable disability, thus gravely burdening the global economy. Irreversible loss of hair cells is a main cause of sensorineural hearing loss, and currently, the only relatively effective clinical treatments are limited to digital hearing equipment like cochlear implants and hearing aids, but these are of limited benefit in patients. It is therefore urgent to understand the mechanisms of damage repair in order to develop new neuroprotective strategies. At present, how to promote the regeneration of functional hair cells is a key scientific question in the field of hearing research. Multiple signaling pathways and transcriptional factors trigger the activation of hair cell progenitors and ensure the maturation of newborn hair cells, and in this article, we first review the principal mechanisms underlying hair cell reproduction. We then further discuss therapeutic strategies involving the co-regulation of multiple signaling pathways in order to induce effective functional hair cell regeneration after degeneration, and we summarize current achievements in hair cell regeneration. Lastly, we discuss potential future approaches, such as small molecule drugs and gene therapy, which might be applied for regenerating functional hair cells in the clinic.

Temporal-spatial Generation of Astrocytes in the Developing Diencephalon / 神经科学通报·英文版

Astrocytes are the largest glial population in the mammalian brain. However, we have a minimal understanding of astrocyte development, especially fate specification in different regions of the brain. Through lineage tracing of the progenitors of the third ventricle (3V) wall via in-utero electroporation in the embryonic mouse brain, we show the fate specification and migration pattern of astrocytes derived from radial glia along the 3V wall. Unexpectedly, radial glia located in different regions along the 3V wall of the diencephalon produce distinct cell types: radial glia in the upper region produce astrocytes and those in the lower region produce neurons in the diencephalon. With genetic fate mapping analysis, we reveal that the first population of astrocytes appears along the zona incerta in the diencephalon. Astrogenesis occurs at an early time point in the dorsal region relative to that in the ventral region of the developing diencephalon. With transcriptomic analysis of the region-specific 3V wall and lateral ventricle (LV) wall, we identified cohorts of differentially-expressed genes in the dorsal 3V wall compared to the ventral 3V wall and LV wall that may regulate astrogenesis in the dorsal diencephalon. Together, these results demonstrate that the generation of astrocytes shows a spatiotemporal pattern in the developing mouse diencephalon.

Force-induced Caspase-1-dependent pyroptosis regulates orthodontic tooth movement / 国际口腔科学杂志·英文版

Pyroptosis, an inflammatory caspase-dependent programmed cell death, plays a vital role in maintaining tissue homeostasis and activating inflammatory responses. Orthodontic tooth movement (OTM) is an aseptic force-induced inflammatory bone remodeling process mediated by the activation of periodontal ligament (PDL) progenitor cells. However, whether and how force induces PDL progenitor cell pyroptosis, thereby influencing OTM and alveolar bone remodeling remains unknown. In this study, we found that mechanical force induced the expression of pyroptosis-related markers in rat OTM and alveolar bone remodeling process. Blocking or enhancing pyroptosis level could suppress or promote OTM and alveolar bone remodeling respectively. Using Caspase-1-/- mice, we further demonstrated that the functional role of the force-induced pyroptosis in PDL progenitor cells depended on Caspase-1. Moreover, mechanical force could also induce pyroptosis in human ex-vivo force-treated PDL progenitor cells and in compressive force-loaded PDL progenitor cells in vitro, which influenced osteoclastogenesis. Mechanistically, transient receptor potential subfamily V member 4 signaling was involved in force-induced Caspase-1-dependent pyroptosis in PDL progenitor cells. Overall, this study suggested a novel mechanism contributing to the modulation of osteoclastogenesis and alveolar bone remodeling under mechanical stimuli, indicating a promising approach to accelerate OTM by targeting Caspase-1.

Human ESC-derived vascular cells promote vascular regeneration in a HIF-1α dependent manner

Hypoxia-inducible factor (HIF-1α), a core transcription factor responding to changes in cellular oxygen levels, is closely associated with a wide range of physiological and pathological conditions. However, its differential impacts on vascular cell types and molecular programs modulating human vascular homeostasis and regeneration remain largely elusive. Here, we applied CRISPR/Cas9-mediated gene editing of human embryonic stem cells and directed differentiation to generate HIF-1α-deficient human vascular cells including vascular endothelial cells, vascular smooth muscle cells, and mesenchymal stem cells (MSCs), as a platform for discovering cell type-specific hypoxia-induced response mechanisms. Through comparative molecular profiling across cell types under normoxic and hypoxic conditions, we provide insight into the indispensable role of HIF-1α in the promotion of ischemic vascular regeneration. We found human MSCs to be the vascular cell type most susceptible to HIF-1α deficiency, and that transcriptional inactivation of ANKZF1, an effector of HIF-1α, impaired pro-angiogenic processes. Altogether, our findings deepen the understanding of HIF-1α in human angiogenesis and support further explorations of novel therapeutic strategies of vascular regeneration against ischemic damage.