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Editorial: Physical Activity: An Optimizer of the Neurophysiological System?
Publication . Fuentes-García, Juan Pedro; Ramirez-Campillo, Rodrigo; Garzón-Camelo, Mauricio; Castro, Maria António
From the field of neurophysiology, broadly defined as the study of the nervous system function, numerous researches have studied the central and peripheral nervous systems from whole organs to subcellular compartments.
The main objective of this Research Topic was to gather studies that shed more light on the benefits of physical exercise in the neurophysiological system, from childhood to old age and from the field of health to sports or professional performance.
Effects of thermal stress on the immune and oxidative stress responses of juvenile sea cucumber Holothuria scabra
Publication . Kamyab, Elham; Kühnhold, Holger; Novais, Sara C.; Alves, Luís M. F.; Indriana, Lisa; Kunzmann, Andreas; Slater, Matthew; Lemos, Marco F. L.
Holothuria scabra is the most valued and cultured tropical sea cucumber, given the great demand of this species for human consumption. However, despite its ecological and economic relevance, little is known regarding its immune responses under thermal stress. Here, the main goal was to study the response of sea cucumbers to temperature stress, assessing sub-organismal alterations and acclimation capacities of juveniles to temperature changes. After changing temperature (1 °C/day) for 6 days, organisms were exposed to temperature conditions of 21 °C (cold), 27 °C (control), and 33 °C (warm) over a 30 day period. At each 15-day interval (T0, T15, and T30), six replicates per condition were killed for biochemical analysis. Immune responses were addressed by studying the activity of phenoloxidase (PO) and prophenoloxidase (ProPO) in the coelomic fluid. Antioxidant defence responses-catalase (CAT), superoxide dismutase (SOD), and glutathione reductase (GR) enzymatic activities-were measured in the muscle and respiratory tree tissues, whereas oxidative damage was evaluated by measuring levels of superoxide radicals (ROS), DNA-strand breaks and lipid peroxidation (LPO). Juvenile H. scabra increased SOD and PO activities when temperature was elevated, and revealed low levels of ROS and damage in both cold and warm treatments throughout the experiment, confirming the organism's moderate thermal stress. After the short acclimation period, the immune and antioxidant responses prevented damage and maintained homeostasis. This multi-biomarker approach highlights its usefulness to monitor the health of H. scabra and to gain insight concerning the use of this high-valued species in global-scale aquaculture from different temperature regions.
Relationship between Postural Reeducation Technique During Sleep and Relaxation Technique in Sleep Quality
Publication . Desouzart, Gustavo; Filgueiras, Ernesto; Matos, Rui
The common sense warn that the quality of our day depends on the quality of our previous night. Among the main factors contributing to a better sleep quality is the postural behavior during the sleep period. However, little or nothing is known about the actual influence of these behaviors on people sleep quality. This paper presents a study which aims to: i) Check if people can take on a new postural behavior during the sleep period after a training period aware of this behavior and; ii) Check if a postural recommendations can aims to induce positive changes in the perception on the indices of Sleep quality in young adults, according to ecological and environmental approach. A sample of 21560 observations, which corresponds to 595 hours of sleep hours of 24 young adults, 12 male military and 12 female undergraduate, participated in this study. The Pittsburgh Sleep Quality Index (PSQI) was used to measure the perception of sleep quality before and after six consecutive months of appliance of the Postural Intervention program. Results shown that the Postural reeducation group improved self-perception of sleep quality (from bad to good) and a significant difference between the periods of the study (p = 0.008), according to the Student's T-Test and, ideal posture while sleeping using the ideal placement and amount of pillows (1.34% to 81.48%). Findings of this study allow us to suggest to health care professionals, in particular the rehabilitation professionals, new strategies and solutions for ergonomic change in posture in bed and improve the sleep quality indices.
Insulin resistance: a new consequence of altered carotid body chemoreflex?
Publication . Conde, Silvia V.; Ribeiro, Maria J.; Melo, Bernardete F.; Guarino, Maria P.; Sacramento, Joana F.
Metabolic diseases affect millions of individuals across the world and represent a group of chronic diseases of very high prevalence and relatively low therapeutic success, making them suitable candidates for pathophysiological studies. The sympathetic nervous system (SNS) contributes to the regulation of energy balance and energy expenditure both in physiological and pathological states. For instance, drugs that stimulate sympathetic activity decrease food intake, increase resting metabolic rate and increase the thermogenic response to food, while pharmacological blockade of the SNS has opposite effects. Likewise, dysmetabolic features such as insulin resistance, dyslipidaemia and obesity are characterized by a basal overactivation of the SNS. Recently, a new line of research linking the SNS to metabolic diseases has emerged with the report that the carotid bodies (CBs) are involved in the development of insulin resistance. The CBs are arterial chemoreceptors that classically sense changes in arterial blood O2 , CO2 and pH levels and whose activity is known to be increased in rodent models of insulin resistance. We have shown that selective bilateral resection of the nerve of the CB, the carotid sinus nerve (CSN), totally prevents diet-induced insulin resistance, hyperglycaemia, dyslipidaemia, hypertension and sympathoadrenal overactivity. These results imply that the beneficial effects of CSN resection on insulin action and glucoregulation are modulated by target-related efferent sympathetic nerves through a reflex that is initiated in the CBs. It also highlights modulation of CB activity as a putative future therapeutic intervention for metabolic diseases.
Survival of Corbicula fluminea (Müller, 1774) in a natural salinity and temperature gradient: a field experiment in a temperate estuary
Publication . Crespo, Daniel; Leston, Sara; Martinho, Filipe; Pardal, Miguel A.; Dolbeth, Marina
The invasive bivalve Corbicula fluminea is described as a freshwater species but can colonize estuarine upper reaches. In a 46-day field experiment, the survival ability of the species along an estuarine gradient was tested. Our goal was to understand its tolerance limits in a transitional area and in which conditions a potential invasion in the estuary could thrive, in order to predict the potential threat of the species distribution and settlement along the freshwater–estuarine continuum. The Lethal Time (LT) method was adapted to this field test with success. The population held an adult stock in the most upstream areas of the estuary (salinity <0.5). Dispersal mechanisms allowed the species to be present in the downstream areas, however, with a different population structure as consequence of the interaction of the diverse physico-chemical gradients of the estuary, in particular different salinity and temperature combinations. During winter, the species was able to survive in all test sites, with practically no mortality, while in summer LT50 (median lethal time) changed considerably when comparing the upstream and the most downstream sites [82 days (predicted value) vs. 9 days, respectively]. Still, 100% mortality was never achieved, adding concern to the species invasion potential in this estuary.