%0 Journal Article
%T Treadmill Exercise Induces Hippocampal Astroglial Alterations in Rats
%A Caren Bernardi
%A Ana Carolina Tramontina
%A Patr¨ªcia Nardin
%A Regina Biasibetti
%A Ana Paula Costa
%A Adriana Fernanda Vizueti
%A Cristiane Batassini
%A Lucas Silva Tortorelli
%A Krista Min¨¦ia Wartchow
%A M¨¢rcio Ferreira Dutra
%A Larissa Bobermin
%A Patr¨ªcia Sesterheim
%A Andr¨¦ Quincozes-Santos
%A Jaqueline de Souza
%A Carlos Alberto Gon£¿alves
%J Neural Plasticity
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/709732
%X Physical exercise effects on brain health and cognitive performance have been described. Synaptic remodeling in hippocampus induced by physical exercise has been described in animal models, but the underlying mechanisms remain poorly understood. Changes in astrocytes, the glial cells involved in synaptic remodeling, need more characterization. We investigated the effect of moderate treadmill exercise (20£¿min/day) for 4 weeks on some parameters of astrocytic activity in rat hippocampal slices, namely, glial fibrillary acidic protein (GFAP), glutamate uptake and glutamine synthetase (GS) activities, glutathione content, and S100B protein content and secretion, as well as brain-derived neurotrophic factor (BDNF) levels and glucose uptake activity in this tissue. Results show that moderate treadmill exercise was able to induce a decrease in GFAP content (evaluated by ELISA and immunohistochemistry) and an increase in GS activity. These changes could be mediated by corticosterone, whose levels were elevated in serum. BDNF, another putative mediator, was not altered in hippocampal tissue. Moreover, treadmill exercise caused a decrease in NO content. Our data indicate specific changes in astrocyte markers induced by physical exercise, the importance of studying astrocytes for understanding brain plasticity, as well as reinforce the relevance of physical exercise as a neuroprotective strategy. 1. Introduction Studies have shown that physical exercise can have profound effects on cardiovascular, pulmonary, and the musculoskeletal system, as well as the central nervous system (CNS) [1, 2]. Moderate physical activity improves memory and learning [3¨C8] and is associated with a lower risk for Alzheimer's dementia [9], Parkinson's disease [10] and other types of neurodegenerative diseases [2]. One of the regions of CNS more affected by exercise is the hippocampus. A putative mechanism, through which the exercise exerts its effects on the hippocampus, is the induction of brain-derived neurotrophic factor (BDNF) [11]. Astrocytes, the most abundant glial cells, particularly those of the glutamatergic type, are very important elements in neurotransmission [12, 13] and antioxidant defense, and this action involves the synthesis and secretion of glutathione (GSH) [14]. These cells are responsible for glutamate removal from the synaptic cleft and its conversion, through glutamine synthetase (GS) catalysis, into glutamine for replacement in the neurons. Moreover, increments in energy demand and functional activity during exercise may require functional and structural
%U http://www.hindawi.com/journals/np/2013/709732/