[Effects of total sleep deprivation on attention network conflict and sample entropy analysis of EEG].

Objective: To explore the effects of total sleep deprivation (TSD) on brain attention network and to analyze the effects of sleep deprivation on individual selective attention network conflict effect and electroencephalograph (EEG) sample entropy. Methods: Twenty-five healthy subjects participated in the test from 9: 00am that day to 9: 00pm next day. The subjects completed the attention network task (ANT) before and after TSD, and synchronously recorded the EEG signals. Sample entropy algorithm was used to analyze the changes of EEG complexity in delta, theta, alpha, beta and gamma frequency bands before and after TSD. Results: Compared with before TSD, the reaction time of attention network conflict effect was significantly decreased after TSD (P＜0. 01), and rate was increased significantly (P＜0. 01). Sample entropy analysis of EEG showed that in beta frequency bands, the sample entropy related to attention network conflict control was increased significantly after TSD (P＜0. 01). No significant difference was found in other EEG frequency bands. Conclusion: TSD reduces the effect of brain attention network conflict, reflecting the decline of conflict control ability after 36 h TSD.

[Effect of nano-SiO2 exposure on spatial learning and memory and LTP of hippocampal dentate gyrus in rats].

OBJECTIVE: To study the effect of nano-SiO2 on spatial learning and memory. METHODS: 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. RESULTS: 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). CONCLUSION: 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.

[Effects of retinol acid and triiodothyronine on alleviating the impairment of cognitive function by sleep deprivation].

OBJECTIVE: To explore the effects of retinol acid (RA) and triiodothyronine (T3) on alleviating the impairment of cognitive function by sleep deprivation (SD). METHODS: 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. RESULTS: 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. CONCLUSION: RA and T3 may alleviate the restrain state of neural system after SD by augmenting the expression of Ng protein in hippocampus.