Flávia Gomes Martinez

Gonadal hormone regulation of glial fibrillary acidic protein immunoreactivity in the medial amygdala subnuclei across the estrous cycle and in castrated and treated female rats

The medial amygdala (MeA) is a sexually dimorphic area that modulates neuroendocrine and behavioral activities and where gonadal hormones play an important role in neuron-glial and synaptic plasticity. Immunohistochemistry was used to identify the astrocytic marker glial fibrillary acidic protein (GFAP) in the different MeA subnuclei--anterodorsal (MeAD), posterodorsal (MePD) and posteroventral (MePV)--of intact female rats in the different phases of the estrous cycle and in ovariectomized females treated with hormonal substitutive therapy. Data semi-quantified by optical densitometry showed that, in the proestrus phase, the GFAP immunoreactivity (GFAP-ir) was higher when compared to the other phases of the estrous cycle (P < 0.02). GFAP-ir was also higher in the MePD than in the MeAD or in the MePV (P < 0. 02). In ovariectomized females, injections of estradiol alone or estradiol plus progesterone increased GFAP-ir in the MePD and in the MePV (P < 0.001), but not in the MeAD (P > 0.3), when compared to control data. These findings suggest that astrocytic GFAP in the MeA subnuclei can be affected either by physiological levels or by hormonal manipulation of the ovarian steroids, which may contribute to the plasticity of local and integrated functional activities of these brain areas in female rats.

Efeitos da fadiga muscular induzida por exercícios no tempo de reação muscular dos fibulares em indivíduos sadios

A fadiga muscular (FM) e um fenomeno comum nas atividades esportivas e diarias, resultando numa piora da performance motora. Ela e considerada um dos fatores causadores de lesoes musculo-esqueleticas. A entorse de tornozelo e um exemplo: a FM afetaria tanto o sistema aferente quanto o eferente. Varios estudos tem analisado a influencia da FM no controle neuromuscular (CNM); entretanto, existe pouca pesquisa sobre essa influencia na velocidade de reacao dos musculos. O objetivo deste estudo foi verificar os efeitos da FM no tempo de reacao muscular (TRM) dos musculos fibulares, que sao os primeiros a responder a um estresse em inversao do tornozelo. Foram estudados 14 individuos saudaveis masculinos (idade: 20-35 anos), que tiveram seus TRM avaliados por meio de eletromiografia (EMG) de superficie. O inicio da atividade muscular foi definido como a media de repouso + 3x o desvio-padrao (DP). O TRM dos fibulares foi mensurado apos uma inversao subita de 20o realizada numa plataforma. A inversao subita foi realizada antes e depois da fadiga muscular, que foi induzida por exercicios localizados dos fibulares ate a exaustao. Os resultados mostraram que houve um aumento significativo do tempo de reacao muscular apos a fadiga (p < 0,01). Durante atividades esportivas prolongadas e durante o processo de reabilitacao, deve-se ter cautela na realizacao de tarefas que requeiram respostas musculares extremamente rapidas sob condicoes de fadiga muscular.The muscular fatigue (MF) is a common phenomenon in the daily sports activities that results in a worsening of the motor performance. It is considered one of the major factors for muscle-skeletal damages, such as the ankle sprain, when the MF would affect both the afferent and the efferent systems. Several studies have been analyzing the influence of the MF on the neuromuscular control (NMC). Nevertheless, there are few researches comprising that influence on the velocity of the muscular reaction. The purpose of this study was to check the effects of the MF on the time of the muscular reaction (TMR) in the fibularis muscles, which are the first to respond to an inversion stress of the ankle. Fourteen healthy male individuals (age: 20-35 years) were studied, who had their TMR assessed by means of the surface electromyography (EMG). The beginning of the muscular activity was defined as the mean resting value +3x the standard deviation (SD). The TMR of the fibularis was measured after a sudden 20o inversion performed on a platform. The sudden inversion was performed before and after the muscular fatigue, which was induced through localized exercises of the fibularis up to the exhaustion. The results have shown a significant increase in the time of the muscular reaction after the fatigue (p < 0.01). While performing prolonged sportive activities and during the rehabilitation process, there must be caution to perform tasks that require extremely fast muscular responses.

Effects of the exercise-induced muscular fatigue on the time of muscular reaction of the fibularis in healthy individuals

A fadiga muscular (FM) e um fenomeno comum nas atividades esportivas e diarias, resultando numa piora da performance motora. Ela e considerada um dos fatores causadores de lesoes musculo-esqueleticas. A entorse de tornozelo e um exemplo: a FM afetaria tanto o sistema aferente quanto o eferente. Varios estudos tem analisado a influencia da FM no controle neuromuscular (CNM); entretanto, existe pouca pesquisa sobre essa influencia na velocidade de reacao dos musculos. O objetivo deste estudo foi verificar os efeitos da FM no tempo de reacao muscular (TRM) dos musculos fibulares, que sao os primeiros a responder a um estresse em inversao do tornozelo. Foram estudados 14 individuos saudaveis masculinos (idade: 20-35 anos), que tiveram seus TRM avaliados por meio de eletromiografia (EMG) de superficie. O inicio da atividade muscular foi definido como a media de repouso + 3x o desvio-padrao (DP). O TRM dos fibulares foi mensurado apos uma inversao subita de 20o realizada numa plataforma. A inversao subita foi realizada antes e depois da fadiga muscular, que foi induzida por exercicios localizados dos fibulares ate a exaustao. Os resultados mostraram que houve um aumento significativo do tempo de reacao muscular apos a fadiga (p < 0,01). Durante atividades esportivas prolongadas e durante o processo de reabilitacao, deve-se ter cautela na realizacao de tarefas que requeiram respostas musculares extremamente rapidas sob condicoes de fadiga muscular.The muscular fatigue (MF) is a common phenomenon in the daily sports activities that results in a worsening of the motor performance. It is considered one of the major factors for muscle-skeletal damages, such as the ankle sprain, when the MF would affect both the afferent and the efferent systems. Several studies have been analyzing the influence of the MF on the neuromuscular control (NMC). Nevertheless, there are few researches comprising that influence on the velocity of the muscular reaction. The purpose of this study was to check the effects of the MF on the time of the muscular reaction (TMR) in the fibularis muscles, which are the first to respond to an inversion stress of the ankle. Fourteen healthy male individuals (age: 20-35 years) were studied, who had their TMR assessed by means of the surface electromyography (EMG). The beginning of the muscular activity was defined as the mean resting value +3x the standard deviation (SD). The TMR of the fibularis was measured after a sudden 20o inversion performed on a platform. The sudden inversion was performed before and after the muscular fatigue, which was induced through localized exercises of the fibularis up to the exhaustion. The results have shown a significant increase in the time of the muscular reaction after the fatigue (p < 0.01). While performing prolonged sportive activities and during the rehabilitation process, there must be caution to perform tasks that require extremely fast muscular responses.

A 9-Week Nordic and Free Walking Improve Postural Balance in Parkinson’s Disease

Aerobic training has a neuroprotective effect in people with Parkinson’s disease. Recent evidence indicates that Nordic walking seems a promising alternative due to positive outcomes in functional mobility. However, the effects of Nordic walking compared to free walking on static and functional balance parameters are still unknown. The aim of this study was to evaluate the effects of nine weeks of Nordic and free walking training on static and functional balance. The sample size was 33 individuals with eight dropouts, leaving 25 individuals in the final sample (Nordic Walking, n=14, Free Walking, n=11). The participants underwent two evaluations in the present randomized clinical trial, pre- and post-training, to determine average velocity and root-mean-square values from center of pressure with eyes open and eyes closed. The functional balance showed approximately 5% improvement for the two groups ( p =0.04). The results indicate that nine weeks of Nordic and free walking training were enough to induce improvements in the proprioceptive system and functional balance.

Efectos de la fatiga muscular inducida por ejercicios sobre el tiempo de reacción muscular peronea en individuos sanos

A fadiga muscular (FM) e um fenomeno comum nas atividades esportivas e diarias, resultando numa piora da performance motora. Ela e considerada um dos fatores causadores de lesoes musculo-esqueleticas. A entorse de tornozelo e um exemplo: a FM afetaria tanto o sistema aferente quanto o eferente. Varios estudos tem analisado a influencia da FM no controle neuromuscular (CNM); entretanto, existe pouca pesquisa sobre essa influencia na velocidade de reacao dos musculos. O objetivo deste estudo foi verificar os efeitos da FM no tempo de reacao muscular (TRM) dos musculos fibulares, que sao os primeiros a responder a um estresse em inversao do tornozelo. Foram estudados 14 individuos saudaveis masculinos (idade: 20-35 anos), que tiveram seus TRM avaliados por meio de eletromiografia (EMG) de superficie. O inicio da atividade muscular foi definido como a media de repouso + 3x o desvio-padrao (DP). O TRM dos fibulares foi mensurado apos uma inversao subita de 20o realizada numa plataforma. A inversao subita foi realizada antes e depois da fadiga muscular, que foi induzida por exercicios localizados dos fibulares ate a exaustao. Os resultados mostraram que houve um aumento significativo do tempo de reacao muscular apos a fadiga (p < 0,01). Durante atividades esportivas prolongadas e durante o processo de reabilitacao, deve-se ter cautela na realizacao de tarefas que requeiram respostas musculares extremamente rapidas sob condicoes de fadiga muscular.The muscular fatigue (MF) is a common phenomenon in the daily sports activities that results in a worsening of the motor performance. It is considered one of the major factors for muscle-skeletal damages, such as the ankle sprain, when the MF would affect both the afferent and the efferent systems. Several studies have been analyzing the influence of the MF on the neuromuscular control (NMC). Nevertheless, there are few researches comprising that influence on the velocity of the muscular reaction. The purpose of this study was to check the effects of the MF on the time of the muscular reaction (TMR) in the fibularis muscles, which are the first to respond to an inversion stress of the ankle. Fourteen healthy male individuals (age: 20-35 years) were studied, who had their TMR assessed by means of the surface electromyography (EMG). The beginning of the muscular activity was defined as the mean resting value +3x the standard deviation (SD). The TMR of the fibularis was measured after a sudden 20o inversion performed on a platform. The sudden inversion was performed before and after the muscular fatigue, which was induced through localized exercises of the fibularis up to the exhaustion. The results have shown a significant increase in the time of the muscular reaction after the fatigue (p < 0.01). While performing prolonged sportive activities and during the rehabilitation process, there must be caution to perform tasks that require extremely fast muscular responses.