Contribution of glia cells specifically astrocytes in the pathology of depression: immunohistochemical study in different brain areas.

BACKGROUND: The contribution of glial cells to the pathophysiology of depression is an emerging research purpose. This study investigated the deficits in glial cells, specifically astrocytes in various brain regions, after the development of depression and then after voluntary running in depressed rats. MATERIALS AND METHODS: Forty-five adult male Wistar rats aged 8-10 weeks were used in the study. A depression model was generated through a forced swimming programme; voluntary running was allowed on rat running wheels; and brain sections were taken from the hippocampus, dentate gyrus (DG), medial prefrontal cortex (mPFC) and cerebellar cortex. After immunostaining with specific antibodies immuno-stain, the astrocytes, oligodendroglia and microglial cells were counted, and certain indices relating astrocytes to other glial cells were calculated. Astrocytic morphology was studied, and the optical density (OD) of glial fibrillary acidic protein (GFAP) immuno-expression was measured in different groups. RESULTS: Compared to the control group, animals in the depression group exhibited significant decreases in the mean astrocyte count in all studied brain areas, significant decreases in GFAP OD values in all areas and significantly reduced values for all glial astrocyte indices in the hippocampus, DG and mPFC. Compared to the rats in the depression group, those in the depression/exercise group exhibited significantly elevated mean astrocyte and oligodendroglia counts in all studied areas, significantly elevated GFAP OD values in all studied areas, and non-significant differences in glial astrocyte indices in the hippocampus, mPFC and cerebellar cortex. CONCLUSION: Astrocytes, rather than other glia, constitute a basis for the development and/or relief of depression.

Beneficial effects of voluntary over forced exercise on skeletal muscle structure and myokines' expression.

BACKGROUND: Myokines, a group of small proteins - mainly cytokines, are released by myocytes during muscular contraction and proved to have many biological effects locally or at systemic levels. The main objective was to study the morphological alterations and myokines expression in rat gastrocnemius muscle following forced compared to voluntary muscle contraction. MATERIALS AND METHODS: Thirty-six adult male Wistar rats were divided into three groups: control, voluntary exercise and forced swimming regimen. The experiment last for 3 weeks. The weight of rats and serum corticosterone levels were recorded. The gastrocnemius muscle samples were processed for histological and immunohistochemical study of different myokines. RESULTS: The mean weight of rats showed no statistical difference between groups. Corticosterone level significantly increased after forced exercise. Voluntary exercise muscle fibres appeared hypertrophied with prominent transverse banding and dominating satellite cells. Forced exercise muscle showed atrophied widely spaced muscle fibres and inflammatory cell infiltrate. Voluntary exercise significantly increased optic density of interleukin 6, macrophage inhibitory and brain derived neurotrophic factors, whereas the forced exercise group showed significant decrease in their optic densities. The optic density of vascular endothelial growth factor significantly decreased in the forced exercise group. Forced exercise could be harmful to the skeletal muscle fibres and it decreases the secretion of important myokines. Further, forced exercise significantly increases the serum corticosterone level. CONCLUSIONS: The use of exercise for the attainment of healthy life style or in psycho- or neuro-therapy should follow a thoroughly studied programme for welfare of human health.

Serum levels of adrenomedullin and inflammatory cytokines in women with term idiopathic intrauterine growth restriction.

This study aimed to determine the concentrations of adrenomedullin (AM), tumour necrosis factor (TNF)-α and interleukin (IL)-6 in maternal circulation of full-term idiopathic intrauterine growth restriction (IUGR) in relation to appropriate-for-gestational-age (AGA) and the possible correlation of AM to these cytokines. A case-control study included 50 idiopathic IUGR mothers and 25 AGA, who were evaluated regarding their serum levels of AM, TNF-α and IL-6. We found that women with idiopathic IUGR have significantly higher serum levels of AM, TNF-α and IL-6 (p = 0.008; 0.016; 0.029, respectively) and the level of AM was significantly correlated to serum level of TNF-α (r = 0.417, p = 0.003) but not significantly correlated to IL-6 compared with the AGA group. In conclusion, the significant increase of AM, TNF-α and IL-6 in the idiopathic IUGR group might contribute to the uteroplacental haemodynamic alterations and can serve as a useful biochemical marker. Significant correlation between AM and TNF-α could hypothesise the existence of a complex interaction between AM and this inflammatory cytokine.