ABSTRACT
Objective To study the effect of low intensity pulsed ultrasound on the hippocampus and to study its possible mechanism in mice.Methods Totally 32 adult C57/BL6 mice were randomly divided into the sham group(n=16)and the LIPUS group(n=16).Mice in the sham group were treated with sham operative,while mice in the LIPUS group were treated by low intensity pulsed ultrasound(average power density of 150 mW/cm2).After 7 days of treatment,immunohistochemical(IHC)and western bolt(WB)were used to determine the expression of DCX,GFAP,and Iba1 in the hippocampus,and the behavioral changes of mice in open field test were observed.Results After 7 days of treatment,the results of IHC showed that the number of microglial cells in the LIPUS group were significantly increased,and the difference was statistically significant compared with that in the sham group(P<0.05).The WB results indicated that the expression of Iba 1 protein in hippocampus was significantly increased in LIPUS group compared with that in the sham group(P<0.05).In the meantime,the behavior score of LIPUS group in the open field test was increased significantly(P<0.05).Conclusion Low intensity pulsed ultrasound can increase the number of microglia in the hippocampus and reduce the anxiety of the mice.
ABSTRACT
<p><b>OBJECTIVE</b>To study the effect of electromagnetic pulse (EMP) exposure on permeability of in vitro blood-brain-barrier (BBB) model.</p><p><b>METHODS</b>An in vitro BBB model, established by co-culturing brain microvascular endothelial cells (BMVEC) and astroglial cells (AC) isolated from rat brain, was exposed to EMP at 100 kV/m and 400 kV/m, respectively. Permeability of the model was assayed by measuring the transendothelial electrical resistance (TEER) and the horseradish peroxidase (HRP) transmission at different time points. Levels of BBB tight junction-related proteins were measured at 0, 1, 2, 4, 8, 12, 16, 20, 24 h after EMP exposure by Western blotting.</p><p><b>RESULTS</b>The TEER level was lower in BBB model group than in control group at 12 h after EMP, exposure which returned to its normal level at 24 h. The 24 h recovery process was triphasic and biphasic respectively after EMP exposure at 100 kV/m and 400 kV/m. Following exposure to 400 kV/m EMP, the HRP permeability increased at 1-12 h and returned to its normal level at 24 h. Western blotting showed that the claudin-5 and ZO-1 protein levels were changed after EMP exposure.</p><p><b>CONCLUSION</b>EMP exposure at 100 kV/m and 400 kV/m can increase the permeability of in vitro BBB model and BBB tight junction-related proteins such as ZO-1 and claudin-5 may change EMP-induced BBB permeability.</p>
Subject(s)
Animals , Female , Rats , Blood-Brain Barrier , Radiation Effects , Capillary Permeability , Radiation Effects , Cells, Cultured , Electromagnetic Fields , Rats, Sprague-DawleyABSTRACT
<p><b>OBJECTIVE</b>To study the effect of electromagnetic pulse (EMP) on the permeability of blood-brain barrier, tight junction (TJ)-associated protein expression and localization in rats.</p><p><b>METHODS</b>66 male SD rats, weighing (200 approximately 250) g, were sham or whole-body exposed to EMP at 200 kV/m for 200 pulses. The repetition rate was 1 Hz. The permeability of the blood-brain barrier in rats was assessed by albumin immunohistochemistry. The expression of typical tight junction protein ZO-1 and occludin in both cerebral cortex homogenate and cerebral cortex microvessel homogenate was analyzed by the Western blotting and the distribution of ZO-1 and occludin was examined by immunofluorescence microscopy.</p><p><b>RESULTS</b>In the sham exposure rats, no brain capillaries showed albumin leakage, at 0.5 h after 200 kV/m EMP exposure for 200 pulses; a few brain capillaries with extravasated serum albumin was found, with the time extended, the number of brain capillaries with extravasated serum albumin increased, and reached the peak at 3 h, then began to recover at 6 h. In addition, no change in the distribution of the occludin was found after EMP exposure. Total occludin expression had no significant change compared with the control. However, the expression level of ZO-1 significantly decreased at 1 h and 3 h after EMP exposure in both cerebral cortex homogenate and cerebral cortex microvessel homogenate. Furthermore, immunofluorescence studies also showed alterations in ZO-1 protein localization in cerebral cortex microvessel.</p><p><b>CONCLUSION</b>The EMP exposure (200 kV/m, 200 pulses) could increase blood-brain barrier permeability in rat, and this change is associated with specific alterations in tight junction protein ZO-1.</p>