Effect of Exercise Prior or After Ischemia on the Density of Neurons and Astrocytes in the Brain of Rats

Abstract

The aim of this study was to analyse the density of astrocytes and neurons in the motor areas of the cortex, striatum and hippocampus of rats that performed exercise before or after cerebral ischemia. A total of 36 Wistar rats were separated into two groups: One that was subjected to Middle Cerebral Artery Occlusion (MCAO) and the other that underwent surgical access in the absence of ischemia. Both groups were subdivided into: Animals that underwent exercise prior to MCAO and sham surgery (AI and AC, n = 12); animals that underwent exercise after MCAO and sham surgery (DI and DC, n = 12); and animals that did not undergo exercise (SI and SC, n = 12). The brains of mice were sectioned and stained by the Nissl method for staining of neurons and the astrocytes were labeled by immunohistochemistry with glial fibrillary acidic protein. Physical training was conducted after the surgery for 6 weeks (30 min/day), 5 days per week. The animals exercised before cerebral ischemia showed greater density of neurons in the striatum, in the apex of the dentate gyrus of the hippocampus, in the motor cortex contra lateral to the lesion and more astrocytes in the motor cortex of the cerebral hemispheres compared with the untrained group (p<0.05). The density of neurons in the brain regions analysed remained unchanged in exercised animals from the fourth day after cerebral ischemia when compared with the sedentary group.

Effects of physical exercise on skeletal muscles of rats with cerebral ischemia

“…The trained animals with cerebral ischemia presented a significant reduction in the number of errors committed during the false step test. These data may be associated with a substantial decrease in the cerebral infarction area, as reported by Damazio et al (14). According to Marin et al (24), in addition to reducing the area of cerebral infarction in animals that undergo OMCA, exercise training produces improvement in motor performance and coordination.…”

The Effects of Resistance Exercise on the Cardiorespiratory Tissue of Rats with Parkinson’s Disease

“…Subsequently, they were immersed in a 0.5% cresyl violet solution (neuron-specific marker) for 30 min, followed by dehydration for five min in flasks containing 70% alcohol, 95% alcohol, 100% alcohol, and 100% alcohol. Next, they were cleared in xylene 1 and xylene 2 and dried in ambient air for 24 h. The slides were observed under a microscope (Motic) using a 4× lens, followed by image capture and the qualitative analysis of neuronal degeneration in the substantia nigra [18,19].…”

Efeitos do exercício físico na prevenção e tratamento de lesões por isquemia: uma revisão de literatura

“…Furthermore, the advantages of physical exercise practiced before cerebral ischemia were indicated by several studies, denoting a neuroprotective effect on the brain, in addition to benefits on motor performance 6,7,8 . Angiogenesis in ischemic hearts is also improved when training is used as a treatment, on treadmills, for example, it was able to produce significant improvement in collateral vessel growth in patients with coronary artery disease.…”