ABSTRACT
Objective:To evaluate the effect of propofol on neuronal activity in medial prefrontal cortex (mPFC) during social behavior in sleep-deprived rats.Methods:Sixty SPF healthy male Sprague-Dawley rats, aged 8 weeks, weighing 200-250 g, were divided into 3 groups ( n=20 each) using a random number table method: control group (group Con), chronic sleep deprivation plus natural sleep group (group CSD+ NS), and chronic sleep deprivation plus propofol group (CSD+ Pro). Sleep deprivation model was developed by the modified multiple platform method, and the rats were placed in the sleep-deprivation tank for 20 h a day (14: 00-10: 00) and allowed to sleep naturally for 4 h (10: 00-14: 00) a day for 28 consecutive days.Propofol 40 mg/kg was intraperitoneally injected after sleep deprivation for 28 consecutive days in group CSD+ Pro, while the equal volume of 10% fat emulsion was given instead in group C and group CSD+ NS.Electroencephalographic recordings in cerebral cortical regions were performed on the days 1st, 14th and 28th after sleep deprivation.The apoptotic neurons in mPFC were detected using TUNEL method after the end of sleep deprivation, and the apoptosis index was calculated.A three chamber sociability test was used to detect the social behavior of rats, and local field potential signals in mPFC were collected. Results:Compared with group Con, the percentage of rapid eye movement sleep was significantly increased, the sniffing time preference coefficients in the 2 stages were reduced, the percentage of the β waves and θ waves-band power in mPFC during the social sniffing process was decreased, and the apoptosis index of neurons in mPFC was increased in group CSD+ NS ( P<0.05). Compared with group CSD+ NS, the percentage of rapid eye movement sleep was significantly increased, the sniffing time preference coefficient in the 2 stages was increased, and the percentage of β waves and θ waves-band power in mPFC during the social sniffing process was increased, and the apoptosis index of neurons in mPFC was decreased in group CSD+ Pro ( P<0.05). Conclusions:Propofol inhibits the apoptosis in neurons in mPFC and increases β and θ waves in the mPFC during social interaction after sleep deprivation in sleep-deprived rats, which is helpful in improving sleep deprivation-induced social disorder.
ABSTRACT
AIM:The 50-Hz magnetic field (MF) is a potential health-risk factor.Its effects on the cardiovascular system have not been fully investigated .This study was conducted to explore the effects of long-term exposure to 50-Hz MF on the cardiovascular system . METHODS:In the study , an exposure system was constructed and the distribution of 50-Hz MF was detected .Sixty-four Sprague-Dawley (SD) rats were exposed to 50-Hz MF at 100 μT for 24 weeks, 20 hours per day, while another 64 rats were sham exposed. During the exposure, blood pressure was measured every 4 weeks, and 24 weeks later, echocardiography, cardiac catheterisation and electrocardiography were performed .Moreover , heart and body weight were recorded , while haematoxylin-eosin staining and real-time PCR were conducted .RESULTS:The results showed that compared with the sham group , exposure to 50-Hz MF did not exert any effect on blood pressure, pulse rate, heart rate and cardiac rhythm.Further, echocardiography and cardiac catheterisation showed that there were no significant differences in the cardiac morphology and haemodynamics .In addition , histopathological examination showed that 50-Hz MF exposure had no effect on the structure of hearts .Finally, the expression of the cardiac hypertrophic relative genes did not show any significant differences between 50-Hz MF exposure group and the sham group .CONCLUSION: Taken together , in SD rats, exposure to 50-Hz/100-μT MF for 24 weeks did not show any obvious effects on the cardiovascular system .