Effects of physical exercise on spatial memory and astroglial alterations in the hippocampus of diabetic rats

Abstract

Type 1 diabetes mellitus (T1DM) is associated with neurocognitive dysfunction and astrogliosis. Physical exercise prevents cognitive impairments and induces important brain modifications. The aim of our study was to investigate the effect of treadmill exercise on spatial memory and astrocytic function in the hippocampus of a T1DM model. Fifty-seven Wistar rats were divided into four groups: trained control (TC) (n = 15), non-trained control (NTC) (n = 13), trained diabetic (TD) (n = 14) and non-trained diabetic (NTD) (n = 15). One month after streptozotocin-induced diabetes, exercise groups were submitted to 5 weeks of physical training, and then, all groups were assessed in the novel object-placement recognition task. Locomotor activity was analyzed in the open field apparatus using Any-maze software. The expression of glial fibrillary acidic protein (GFAP) and S100B in hippocampus and cerebrospinal fluid were measured using ELISA assay, and hippocampal GFAP immunoreactivity was evaluated by means of immunohistochemistry and optical densitometry. The results showed that physical exercise prevents and/or reverts spatial memory impairments observed in NTD animals (P < 0.01). Decreased locomotor activity was observed in both the NTD and TD groups when compared with controls (P < 0.05). ELISA and immunohistochemistry analyzes showed there was a reduction in GFAP levels in the hippocampus of NTD animals, which was not found in TD group. ELISA also showed an increase in S100B levels in the cerebrospinal fluid from the NTD group (P < 0.01) and no such increase was found in the TD group. Our findings indicate that physical exercise prevents and/or reverts the cognitive deficits and astroglial alterations induced by T1DM.

Resveratrol prevents akinesia and restores neuronal tyrosine hydroxylase immunoreactivity in the substantia nigra pars compacta of diabetic rats

“…To the best of our knowledge, our study is the first to demonstrate akinesia development in diabetic rodents. Previous experimental evidences have demonstrated bradykinesia in rats with STZ-induced diabetes during the open field test (De Senna et al, 2011;Do Nascimento et al, 2011;Grzeda et al, 2007;Haider et al, 2013). In diabetic patients, psychomotor efficiency and motor speed are cognitive processes that can be negatively affected (Sims-Robinson et al, 2010), and the onset of diabetes prior to the development of PD is considered a risk factor for more severe Parkinsonian clinical symptoms (Cereda et al, 2012), suggesting that diabetes has a negative impact on nigrostriatal physiology.…”

Chronic glucocorticoids exposure enhances neurodegeneration in the frontal cortex and hippocampus via NLRP-1 inflammasome activation in male mice

“…This approach is usually used to measure the exploration, anxiety and locomotor behavior of animals (Koros et al, 1998). The open field test apparatus is a computer-controlled cage (60 Â 60 Â 50 cm, Shanghai Biowill Company) which was separated as 9 squares (8 peripheral and 1 central) by two perpendicular transverse lines and vertical lines as previously described (de Senna et al, 2011). The open field test was initiated by placing a mouse in the central square of the cage for 2 min in each testing period.…”

Physical training improves non-spatial memory, locomotor skills and the blood brain barrier in diabetic rats

“…On the other hand, it is well documented that physical exercise has beneficial neurological effects in diabetes, including improvement in learning, memory and locomotor activity (Reisi et al, 2009;de Senna et al, 2011).…”