Effect of nano-SiO2 exposure on spatial learning and memory and LTP of hippocampal dentate gyrus in rats / 中国应用生理学杂志

<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>

Effects of retinol acid and triiodothyronine on alleviating the impairment of cognitive function by sleep deprivation / 中国应用生理学杂志

<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>

The changes of neurotransmitter content in spinal cord after exercise-induced central fatigue / 中国应用生理学杂志

<p><b>AIM</b>To investigate the changes of neurotransmitter concentration in spinal cord after exercise-induced central fatigue and study the mechanism of central fatigue at spinal level.</p><p><b>METHODS</b>Establish exercise-induced central fatigue model according to Bedford incremental loading training. The rats were divided into three groups, control group (C), immediately after training group (IT), rest 3 hours after training group (RT). Then using high performance liquid chromatography (HPLC) to detect the concentration of neurotransmitter in spinal cord.</p><p><b>RESULTS</b>Amino acid neurotransmitters in spinal cord increased in IT group: Glu, GABA increased significantly (P < 0.05), Gly also increased but have no statistic difference; while in RT group, amino acid neurotransmitters got back to normal. However monoamine neurotransmitters NE, 5-HT tended to decrease in IT group. In RT group 5-HT decreased dramatically (P < 0.05).</p><p><b>CONCLUSION</b>Exercise-induced fatigue changed the concentration of neurotransmitter in spinal cord.The results suggested that neurotransmitter in spinal cord might have relationship with exercise-induced fatigue, especially 5-HT might have more important effect on recovery of fatigue.</p>