ABSTRACT
Objective To observe the changes of the pulmonary ventilation(VE)volume under different exercise intensities along with time,and to explore the best time for measuring VE under different intensities of exercise.Methods Sixty-one young mals were selected as subjects,who engaged in exercise of different intensities on the cycle ergometer(20, 40, 60, 80, 100, 120, 140, 160, and 180 W).The duration of exercise of each intensity was 6 minutes,the cardiopulmonary function was detected using a portable instrument,and real time monitoring of VE changes was enforced. Results (1)For exercise of intensity 20 W, VE initially increased fast with time, but after 1 min,it ceased to rise and remained stable.There was no significant difference at 1 min and afterwards(P>0.05).(2)The case was the same with exercise of the intensity 40 and 60 W.(3)For intensities of 80,100,120,140,and 160 W,VE became stable at 3 min. (4)For exercise of intensity 180 W,VE became stable at 4 min.Conclusion The time taken for VE to achieve stability under different intensities is different,which is positively correlated with the intensity of exercise.The greater the intensity of exercise,the longer it takes to achieve stability.
ABSTRACT
<p><b>OBJECTIVE</b>To study the effect of nano-SiO2 on spatial learning and memory.</p><p><b>METHODS</b>Twenty-four male rats were randomly divided into 3 groups: control group (C group), low dose group (L group) and high dose group (H group). The rats were intragastrically administrated with nanometer particles at 25 and 100 mg/kg body weight every day for 4 weeks. After exposure, the ability of learning and memory of rats was tested by Morris water maze, and electrophysiological brain stereotactic method was used to test long-tear potentiation (LTP) in dentate gyrus (DG) of the rats.</p><p><b>RESULTS</b>The increase rate of body weight in H group was reduced significantly compared with C group ( P < 0.05). In the space exploration experiment of Morris water maze test, the escape latency of H group was longer than that of C group (P < 0.05). The rats of H group spent less time in finding the target quadrant (P < 0.05) . The rate of LP induction of H group was significantly lower than that of C group (P < 0.05). After high fre quency stimulation (HFS), The changes of amplitude of population spike (PS) of L group and H group were lower than those of C group significantly (P < 0.05, P < 0.01).</p><p><b>CONCLUSION</b>Nano-SiO₂may result in impairment of spatial learning and memory ability by reducing the rate of LTP induction and the increase of PS in hippocampus.</p>
Subject(s)
Animals , Male , Rats , Dentate Gyrus , Long-Term Potentiation , Maze Learning , Memory , Nanoparticles , Silicon Dioxide , Spatial LearningABSTRACT
<p><b>OBJECTIVE</b>To explore the effects of retinol acid (RA) and triiodothyronine (T3) on alleviating the impairment of cognitive function by sleep deprivation (SD).</p><p><b>METHODS</b>Male Wistar rats were divided into 4 groups: control group (C group), sleep deprivation group (SD group), sleep deprivation + RA group (SD + RA group) and sleep deprivation + T3 group (SD + T3 group). Open field test (OFT) was used to observe the nervous behavior of the rats after SD and electrophysiological brain stereotactic method was used to test long-term potentiation (LTP) in dentate gyrus (DG) of the rats. Ng protein expression was determined by Western blot.</p><p><b>RESULTS</b>Compared with the SD group, the number of crossing in OFT, the changes of amplitude of population spike (PS) and the expression of Ng protein in hippocampus were higher significantly in the SD + RA and SD + T3 groups. All of these had not significant difference comparing with the C group.</p><p><b>CONCLUSION</b>RA and T3 may alleviate the restrain state of neural system after SD by augmenting the expression of Ng protein in hippocampus.</p>