[Suppression of glutamate neurotoxicity by 5-HT in hippocampal neurons].

The effects of excess glutamate on the survival rate of cultured hippocampal neurons, the population spike (PS) of CA1 area of hippocampal slices and the Ca(2+) current of hippocampal neurons were observed in rats. Decreased survival rate of hippocampal neurons in the presence of excess glutamate was partially reversed by 5-HT, which was in association with a less decrease of PS magnitudes. The Ca(2+) inward current induced by glutamate was significantly diminished in the presence of 5-HT. It is suggested that 5-HT can inhibit excess glutamate-induced neurotoxicity by suppressing the glutamate triggered calcium influx.

[Death manners of primary cultured hippocampal neurons of rats in response to excess corticosterone exposure].

AIM AND METHODS: The death types of rat hippocampal neuronal cells in primary culture under various doses of corticosterone were questioned by in situ staining methods. RESULTS: CORT triggered two cellular death pathways: necrosis and apoptosis. Moreover, high concentrations of CORT increased the necrotic and apoptotic percentages in dose-dependent and time-dependent manners. CONCLUSION: The factors that lead to hippocampal neuronal cells necrosis or apoptosis induced by CORT may be contributed by the impaired of energy metabolism and the vulnerability of neurons to the excess glutamate neurotoxicity.

[Effects of chronic stress on the learning and memory ability and hippocampal LTP in rats].

AIM AND METHODS: A chronic stress model in 21 days with multi-stressors was applied to question the effects of stress on the learning and memory ability and the hippocampal neuronal synaptic plasticity in rats, using the Y maze test and LTP electrophysiological recording in vivo. RESULTS: The impairment of spatial learning and memory ability and an obvious suppression in LTP in hippocampal dentate gyrus was observed in stress group after chronic stress. CONCLUSION: The hippocampal synaptic plasticity may be decreased by the chronic stress. And then, the learning and memory ability may also be impaired consequently.

A new and simple method for concentration of enteric viruses from water.

A new type of electropositive filter media particle was tested to adsorb bacteriophage f2 and enteric viruses from tap water. 3 x nutrient broth (pH 7.2) was used to elute the adsorbed viruses, and the eluate was reconcentrated by polyethylene glycol (Mw 6000) precipitation with a final concentration of 10% (wt./vol.). The adsorption of bacteriophage was reliable and efficient, and not affected by the pH value, temperature, turbidity and organic materials in water. This method gave a recovery of Polio 1 virus 96.0% for small-volume tap water; 88.7% for large-volume water; and gave a comparable recovery of HAV, Coxsackie B3 and Echo 7 from tap water. The concentration method need not acidify virus-containing water, add exogenous multivalent cation salts, or require expensive equipment.