[Act of Arc siRNA via lentivirus on the memory consolidation of amygdala-kindled rats].

OBJECTIVE: To explore the memory consolidation related role of gene Arc in amygdala-kindled rats. METHODS: A total of 60 male amygdala-kindled rats were divided equally into 3 groups: 0.9% sodium chloride injection, null vector lentivirus injection and silencing lentivirus injection. Quantitative polymerase chain reaction (qPCR) and Western blot were performed to confirm the silencing efficiency of Arc. And the passive avoidance test and Morris' water maze were used to test the memory consolidation ability of rats in three groups. RESULTS: The memory consolidation ability became significantly impaired in the Arc silencing group in both of passive avoidance test and water maze comparing to the other groups. And no significant difference existed in memory consolidation ability between 0.9% sodium chloride and null vector lentivirus injection groups. CONCLUSION: The ability of memory consolidation is impaired in Arc silencing amygdala-kindled rats and Arc may play a significant role in the consolidation of memory in amygdala-kindled rats.

[The effects of low-frequency electric stimulus on hippocampal of Effects of low-frequency electric stimulus on hippocampal of α5 subunit of extra synapse GABAA receptor in kainic acid-induced epilepsy rats].

OBJECTIVE: To explore the effects of low-frequency electric stimulus (LFS) on hippocampal of α5 subunit of extrasynaptic GABAA receptor in kainic acid-induced epilepsy rats and explore the possible mechanism of LFS on hippocampus to treat epilepsy. METHODS: A total of 32 male Sprague-Dawley rats were divided randomly into 4 groups:epileptic, pseudo-surgery, LFS treatment and control. The expression of α5 subunit of extrasynaptic GABAA receptor and the association with the curative effects of LFS were evaluated by behavioristics, real-time fluorogenic quantitative polymerase chain reaction (PCR) and Western blot. RESULT: After treatment, the number of seizures in LFS group were significantly lower than that in the epileptic and pseudo-surgery groups (2.88 ± 0.83 vs 8.50 ± 0.93 and 8.88 ± 0.83) (P < 0.01). The results of real-time PCR demonstrated that the expression of mRNA of α5 subunits in LFS treatment group was obviously higher than that in epileptic and pseudo-surgery groups (0.74 ± 0.20 vs 0.30 ± 0.16 and 0.31 ± 0.16) (P < 0.01), but was lower than 1.10 ± 0.23 in control group. Western blot demonstrated that the protein expression of α5 subunits in LFS (0.75 ± 0.09) and control (0.88 ± 0.09) groups were dramatically higher than that in epileptic (0.22 ± 0.08) and pseudo-surgery (0.26 ± 0.08) groups (P < 0.01). CONCLUSION: Low-frequency electric stimulus on hippocampus is effective in controlling epileptic seizures. And the mechanism may be related with the expression level of α5 subunits of extrasynaptic GABAA receptor.

Relationship between the transmission of schistosomiasis japonica and the construction of the Three Gorge Reservoir.

OBJECTIVE: To study the relationship between the changes of environment and the transmission of Schistosomiasis japonica after the construction of the Three Gorge Reservoir. METHODS: On the basis of the predictive data on changes of water level and sediment in the middle and lower reaches of the Yangtze River after the dam construction provided by the Yangtze River Committee on Water Conservancy, corresponding data were collected and analyzed. In order to understand the effects of changes of water level and sediment on Oncomelania hupensis, the intermediate host of Schistosoma japonicum, field surveys and ecologically intimated experiments were done. The prevalence status and factors related to transmission were investigated by epidemiology, medical geography and public health. RESULTS: Positive impact on control of schistosomiasis is that floods in the Yangtze River will occur less and will decrease the dispersal of snails and the chances of infection for humans and animals as well. Snail habitats' beach will be reduced in the flushed area along the Yangtze River. Exploitation of beach and elimination of snails will benefit from the beach's uplift in flushed area. The floods ahead of time in autumn will interfere with the development of snails. Negative impact is that the flushed beaches and migratory settlements at certain altitude may become snail habitats. So the reservoir area will be a potential transmission area of schistosomiasis due to dispersal of infectious resources and Oncomelania snails. The uprising of the water body level may cause the expending of the snail habitats in some places of Jianghan plain during the transition of spring to summer. The destruction of the embankments of the Dongting Lake will be put off by its delayed flush, which causes the beach in a situation of growing reed-grass or grass for a long time that benefits the reproduction of the snails. The chances for schistosome infection to humans and animals will be on the increase, because the water regression occurs ahead of time in the Dongting Lake beach in autumn. The distribution of snails will not be affected by the changes of water level in the lower reaches of the Yangtze River after the dam is built, but the flushed section in Anhui in the recent 80 years are suitable for the snails' development. The environmental changes due to dam construction will not obviously affect the development of snails and the transmission of schistosomiasis in the Poyang Lake area. CONCLUSION: The construction of the huge dam and the formation of the Three Gorge Reservoir on the Yangtze River may have both positive and negative impact on schistosomiasis transmission and control. Great effort must be made to decrease the negative impact to avoid or, at least, to decrease S. japonicum transmission.