Single axonal characterization of trigeminocerebellar projection patterns in the mouse.

The cerebellar projection from the trigeminal nuclear complex is one of the major populations of the cerebellar inputs. Although this projection is essential in cerebellar functional processing and organization, its morphological organization has not been systematically clarified. The present study addressed this issue by lobule-specific retrograde neuronal labeling and single axonal reconstruction with anterograde labeling. The cerebellar projection arose mainly from the interpolaris subdivision of the spinal trigeminal nucleus (Sp5I) and the principal trigeminal sensory nucleus (Pr5). Although crus II, paramedian lobule, lobule IX, and simple lobule were the major targets, paraflocculus, and other lobules received some projections. Reconstructed single trigeminocerebellar axons showed 77.8 mossy fiber terminals on average often in multiple lobules but no nuclear collaterals. More terminals were located in zebrin-negative or lightly-positive compartments than in zebrin-positive compartments. While Pr5 axons predominantly projected to ipsilateral crus II, Sp5I axons projected either predominantly to crus II and paramedian lobule often bilaterally, or predominantly to lobule IX always ipsilaterally. Lobule IX-predominant-type Sp5I neurons specifically expressed Gpr26. Gpr26-tagged neuronal labeling produced a peculiar mossy fiber distribution, which was dense in the dorsolateral lobule IX and extending transversely to the dorsal median apex in lobule IX. The projection to the cerebellar nuclei was observed in collaterals of ascending Sp5I axons that project to the diencephalon. In sum, multiple populations of trigeminocerebellar projections showed divergent projections to cerebellar lobules. The projection was generally complementary with the pontine projection and partly matched with the reported orofacial receptive field arrangement.

Neurogenic timing of the inferior olive subdivisions is related to the olivocerebellar projection topography.

The olivocerebellar projection is organized into an intricate topographical connection from the inferior olive (IO) subdivisions to the longitudinally-striped compartments of cerebellar Purkinje Cells (PCs), to play an essential role in cerebellar coordination and learning. However, the central mechanisms for forming topography need to be clarified. IO neurons and PCs are generated during overlapping periods of a few days in embryonic development. Therefore, we examined whether their neurogenic timing is specifically involved in the olivocerebellar topographic projection relationship. First, we mapped neurogenic timing in the entire IO by using the neurogenic-tagging system of neurog2-CreER (G2A) mice and specific labeling of IO neurons with FoxP2. IO subdivisions were classified into three groups depending on their neurogenic timing range. Then, we examined the relationships in the neurogenic-timing gradient between IO neurons and PCs by labeling topographic olivocerebellar projection patterns and PC neurogenic timing. Early, intermediate, and late groups of IO subdivisions projected to late, intermediate, and early groups of the cortical compartments, respectively, except for a few particular areas. The results indicated that the olivocerebellar topographic relationship is essentially arranged according to the reverse neurogenic-timing gradients of the origin and target.

Physical fitness training and reaction speed in sports table tennis players / Treinamento de aptidão física e velocidade de reação nos jogadores de tênis de mesa esportivo / Entrenamiento de aptitud física y velocidad de reacción en jugadores de tenis de mesa deportivo

ABSTRACT Introduction: Table tennis is demanding in terms of athletes' physical fitness and muscular responsiveness. Excellent physical fitness is important to ensure a high technical level. It can also play an essential role in injury prevention. Objective: Explore the correlation between table tennis players' movements and their displacements. Methods: Volunteer professional competitors underwent a private 16-week quality speed training program. In this experiment, athletes had their speed analyzed before and after training. Mathematical and statistical analyses were performed on the collected data. Some discussions are made to improve the reflex ability of the athletes. Results: The table tennis players' physical fitness and action response capacity were explored. After physical exercise, the players' reflex ability improved. There were statistically significant differences in the data (P<0.05). Conclusion: The results show that special training improves athletes' reaction speed, endurance, strength, coordination, and flexibility. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

RESUMO Introdução: O tênis de mesa é um esporte exigente quanto à aptidão física e à capacidade de resposta muscular do atleta. A excelente aptidão física é importante para assegurar o elevado nível técnico. Também pode desempenhar um papel essencial na prevenção de lesões. Objetivo: Explorar a correlação entre os movimentos dos jogadores de tênis de mesa e seus deslocamentos. Métodos: Competidores profissionais voluntários foram submetidos a um programa particular de treinamento de qualidade de velocidade com 16 semanas de duração. Nesta experiência, os atletas tiveram sua velocidade analisada antes e depois do treinamento. Análises matemáticas e estatísticas foram realizadas sobre os dados coletados. Algumas discussões são feitas para melhorar a capacidade no reflexo dos atletas. Resultados: Explorou-se a aptidão física dos jogadores de tênis de mesa e a capacidade de resposta à ação. Após o exercício físico, a capacidade de reflexão dos jogadores melhorou. Houve diferenças estatisticamente significativas nos dados (P<0,05). Conclusão: Os resultados mostram que o treinamento especial desenvolvido melhora a velocidade de reação dos atletas, a resistência, a força, a coordenação e a flexibilidade. Nível de evidência II; Estudos terapêuticos - investigação dos resultados do tratamento.

RESUMEN Introducción: El tenis de mesa es un deporte exigente en cuanto a la forma física y la capacidad de respuesta muscular del deportista. Una excelente forma física es importante para garantizar el alto nivel técnico. También puede desempeñar un papel esencial en la prevención de lesiones. Objetivo: Explorar la correlación entre los movimientos de los jugadores de tenis de mesa y sus desplazamientos. Métodos: Se sometió a competidores profesionales voluntarios a un programa de entrenamiento de calidad de velocidad particular de 16 semanas de duración. En este experimento, se analizó la velocidad de los atletas antes y después del entrenamiento. Se realizaron análisis matemáticos y estadísticos de los datos recogidos. Se hacen algunas discusiones para mejorar la capacidad en el reflejo de los atletas. Resultados: Se exploró la aptitud física y la capacidad de respuesta a la acción de los jugadores de tenis de mesa. Tras el ejercicio físico, la capacidad de reflejo de los jugadores mejoró. Hubo diferencias estadísticamente significativas en los datos (P<0,05). Conclusión: Los resultados muestran que el entrenamiento especial desarrollado mejora la velocidad de reacción, la resistencia, la fuerza, la coordinación y la flexibilidad de los atletas. Nivel de evidencia II; Estudios terapéuticos - investigación de los resultados del tratamiento.