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Astrocytic changes have been demonstrated in several neurodegenerative diseases, showing that these cells play an important role in functional recovery/maintenance against brain damage. Physical exercise is known to contribute to this process; however, the cellular mechanisms involved are not fully understood. This study investigated the effects of physical exercise on motor deficits and the expression of glial fibrillary acidic protein (GFAP) in a model of Parkinson's disease (PD). Rats were divided into four groups: sham sedentary (SS) and sham trained (ST); lesioned sedentary (LS) and lesioned trained (LT). 6-OHDA was infused unilaterally into the medial forebrain bundle. Behavioral tasks were applied to evaluate motor abilities. Tyrosine hydroxylase (TH-in substantia nigra) and GFAP (in striatum) immunoreactivities (ir) were semi-quantified using optical density. The animals submitted to treadmill training completed fewer pharmacological-induced rotations when compared with sedentary animals and they also showed ameliorated motor impairments. Interestingly, although no change in TH-ir, the exercise led to restored striatal GFAP expression in the LT group while there was no effect in the ST group. This study is the first study to show data indicating the recovery of GFAP expression post-exercise in this model and further research is necessary to determine the precise action mechanisms of exercise on astrocytes in the PD.

Cerebral palsy (CP) is a disorder of locomotion, posture and movement that can be caused by prenatal, perinatal or postnatal insults during brain development. An increased incidence of CP has been correlated to perinatal asphyxia and maternal infections during gestation. The effects of maternal exposure to low doses of bacterial endotoxin (lipopolysaccharide, LPS) associated or not with perinatal anoxia (PA) in oxidative and inflammatory parameters were examined in cerebral cortices of newborns pups. Concentrations of TNF-α, IL-1, IL-4, SOD, CAT and DCF were measured by the ELISA method. Other newborn rats were assessed for neonatal developmental milestones from day 1 to 21. Motor behavior was also tested at P29 using open-field and Rotarod. PA alone only increased IL-1 expression in cerebral cortex with no changes in oxidative measures. PA also induced a slight impact on development and motor performance. LPS alone was not able to delay motor development but resulted in changes in motor activity and coordination with increased levels of IL-1 and TNF-α expression associated with a high production of free radicals and elevated SOD activity. When LPS and PA were combined, changes on inflammatory and oxidative stress parameters were greater. In addition, greater motor development and coordination impairments were observed. Prenatal exposure of pups to LPS appeared to sensitize the developing brain to effects of a subsequent anoxia insult resulting in an increased expression of pro-inflammatory cytokines and increased free radical levels in the cerebral cortex. These outcomes suggest that oxidative and inflammatory parameters in the cerebral cortex are implicated in motor deficits following maternal infection and perinatal anoxia by acting in a synergistic manner during a critical period of development of the nervous system.

The serotoninergic system modulates nociceptive and locomotor spinal cord circuits. Exercise improves motor function and changes dopaminergic, noradrenergic, and serotonergic central systems. However, the direct relationship between serotonin, peripheral nerve lesion and aerobic treadmill exercise has not been studied. Using immunohistochemistry and optic densitometry, this study showed that the sciatic nerve transection increased the serotoninergic immunoreactivity in neuronal cytoplasm of the magnus raphe nuclei of trained and sedentary rats. In the dorsal raphe nucleus the increase only occurred in sedentary-sham-operated rats. In the spinal cord of trained, transected rats, the ventral horn showed significant changes, while the change in dorsal horn was insignificant. Von Frey's test indicated analgesia in all exercise-trained rats. The sciatic nerve functional index indicated recovery in the trained group. Thus, both the aerobic treadmill exercise training and the nervous lesion appear to contribute to changes in serotonin immunoreactivity.

The intracerebroventricular infusion of streptozotocin (icv-STZ) has been largely used in research to mimic the main characteristics of Alzheimer's disease (AD), including cognitive decline, impairment of cholinergic transmission, oxidative stress and astrogliosis. Moderate physical exercise has a number of beneficial effects on the central nervous system, as demonstrated both in animals and in human studies. This study aimed to evaluate the effect of 5-week treadmill training, in the icv-SZT model of sporadic AD, on cognitive function, oxidative stress (particularly mediated by NO) and on the astrocyte marker proteins, glial fibrillary acidic protein (GFAP) and S100B. Results confirm the spatial cognitive deficit and oxidative stress in this model, as well as astroglial alterations, particularly a decrease in CSF S100B. Physical exercise prevented these alterations, as well as increasing the hippocampal content of glutathione and GFAP per se in the CA1 region. These findings reinforce the potential neuroprotective role of moderate physical exercise. Astroglial changes observed in this dementia model contribute to understanding AD and other diseases that are accompanied by cognitive deficit.

The findings indicate that balance and coordination training improves sciatic nerve regeneration, suggesting that it is possible to revert and/or prevent soleus muscle atrophy and improve performance on sensorimotor tests.