Treadmill Exercise Induces Hippocampal Astroglial Alterations in Rats

Caren Bernardi,Larissa Bobermin,Patrícia Sesterheim,Ana Carolina Tramontina,Lucas Silva Tortorelli,André Quincozes-Santos,Krista Minéia Wartchow,Regina Biasibetti,Patrícia Nardin,Adriana Fernanda Vizueti,Cristiane Batassini,Ana Paula Costa,Jaqueline De Souza,Carlos Alberto Gonçalves,Márcio Ferreira Dutra

doi:10.1155/2013/709732

Abstract

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.

Highlights

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]
A putative mechanism, through which the exercise exerts its effects on the hippocampus, is the induction of brain-derived neurotrophic factor (BDNF) [11]
Astrocytes have been shown to play an important role in synaptic remodeling [40,41,42] and protecting the CNS against various pathologies [43]. e aim of this study was to evaluate the effect of moderate treadmill running on astroglial parameters in the rat hippocampus

Summary

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]. 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, 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]. Increments in energy demand and functional activity during exercise may require functional and structural alterations in astrocytes [15, 16], due to their involvement in the blood brain barrier [17]

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Discussion

Conclusion