[Objective] The research aimed to study the effects of microwave on the chick embryo development and the cognitive function of chickling. [Method] The microwave which was transmitted by the permatron and was 2 450 MHz...[Objective] The research aimed to study the effects of microwave on the chick embryo development and the cognitive function of chickling. [Method] The microwave which was transmitted by the permatron and was 2 450 MHz was used to simulate the microwave radiation source to radiate the hatching eggs until the chickling was hatched out. The disposable passive avoidance learning and RT-PCR were respectively used to detect the influences of microwave on the cognitive function of chickling and the expression amounts of NMDA receptor NR1 and NR2 subunits. [Result] After the microwave radiation,the avoidance rate of exposed group was significantly lower than that in the control group. Especially the avoidance rate of highest radiation intensity group was extremely significantly lower than that in the control group. Meanwhile,the body weights of two groups of chickling in the exposed group increased,and the hatching time in one group increased. Via RT-PCR analysis,the expression amount of NR2 subunit increased on the 10th day and the 15th day. The expression amount of NR1 subunit only decreased on the 15th day. [Conclusion] The microwave had the certain influence on the individual development. By changing the structure composition and function of NMDA receptor in the endbrain,the microwave made the self-regulation ability of chickling decline,which had the certain damage on the cognitive function.展开更多
Objective To study the effect of salicylate on the expression and function of NMDA receptors in spiral ganglion neurons （SGNs）. Methods The mRNA of NR1 subunit of NMDA receptor in modiolus tissues were detected by R...Objective To study the effect of salicylate on the expression and function of NMDA receptors in spiral ganglion neurons （SGNs）. Methods The mRNA of NR1 subunit of NMDA receptor in modiolus tissues were detected by Real time fluorescence quantitative PCR （FQ-PCR）. NMDA receptor whole-cell currents were recorded using patch clamp in acute isolated SGNs. Results Compared with the control group, salicylate significantly increased the mRNA level of NR1 subunit in SGNs. NMDA of concentrations ranging from 0.1 mM to 10 mM evoked no current in SGNs. NMDA （0. 1mM and 0.5 mM） applied with salicylate （5 mM）, however, induced inward currents （212.6±15.2pA, n=5; 607.9±44.3pA, n=5） in a dose-dependent manner, which could be inhibited by APV. Salicylate alone did not produce any current in SGNs. Conclusion Salicylate increases the expression of NMDA receptors and facilitates the currents mediated by NMDA receptors in SGNs.展开更多
Objective Glycine acts as a co-agonist for the activation of N-methyl-D-aspartate receptors （NMDARs） by binding to glycine sites, thus potentiating glutamate-elicited responses and inhibiting NMDAR desensitization i...Objective Glycine acts as a co-agonist for the activation of N-methyl-D-aspartate receptors （NMDARs） by binding to glycine sites, thus potentiating glutamate-elicited responses and inhibiting NMDAR desensitization in a dose-dependent manner. The present study aimed to characterize the glycine-dependent inactivation of NMDARs and to explore its pathophysiological significance. Methods Primary hippocampal cell cultures from embryonic days 17-18 rats were treated with NMDA or NMDA plus glycine. Patch-clamp recording and intracellular Ca 2＋ imaging were performed to test the effects of glycine on NMDA-activated currents and increase of intracellular free Ca 2＋ respectively. Immunofluorescence staining was conducted to examine NR1 internalization. Cell damage was tested with MTT method and lactate dehydrogenase leakage. Results Glycine reduced the peak current and Ca 2＋ influx elicited by NMDA application at concentrations ≥300 μmol/L. This is a novel suppressive influence of glycine on NMDAR function, since it occurs via the NMDAR glycine-binding site, in contrast to the classic suppression, which occurs through the binding of glycine to glycine receptors. The level of membrane NMDARs was measured to evaluate whether internalization was involved. Immunohistochemical labeling showed that incubation with high concentrations of NMDA plus glycine did not change the expression of NMDARs on the cell surface when compared to the expression without glycine; hence the possibility of NMDAR internalization primed by glycine binding was excluded. Conclusion In summary, the novel suppressive effect of glycine on NMDARs was mediated via binding to the glycine site of the NMDAR and not by activation of the strychnine-sensitive glycine-receptor-gated chloride channel or by the internalization of NMDARs. The inhibitory influence of glycine on NMDARs adds a new insight to our knowledge of the complexity of synaptic transmission.展开更多
基金Supported by Suzhou City Science and Technology Bureau Item(YJS0904)~~
文摘[Objective] The research aimed to study the effects of microwave on the chick embryo development and the cognitive function of chickling. [Method] The microwave which was transmitted by the permatron and was 2 450 MHz was used to simulate the microwave radiation source to radiate the hatching eggs until the chickling was hatched out. The disposable passive avoidance learning and RT-PCR were respectively used to detect the influences of microwave on the cognitive function of chickling and the expression amounts of NMDA receptor NR1 and NR2 subunits. [Result] After the microwave radiation,the avoidance rate of exposed group was significantly lower than that in the control group. Especially the avoidance rate of highest radiation intensity group was extremely significantly lower than that in the control group. Meanwhile,the body weights of two groups of chickling in the exposed group increased,and the hatching time in one group increased. Via RT-PCR analysis,the expression amount of NR2 subunit increased on the 10th day and the 15th day. The expression amount of NR1 subunit only decreased on the 15th day. [Conclusion] The microwave had the certain influence on the individual development. By changing the structure composition and function of NMDA receptor in the endbrain,the microwave made the self-regulation ability of chickling decline,which had the certain damage on the cognitive function.
基金supported by a grant from National Nature Science Fund of China(No.81060082,30860098)Nature Science Fund of Guangxi(No.2011jjA40056)to Jiping Su
文摘Objective To study the effect of salicylate on the expression and function of NMDA receptors in spiral ganglion neurons （SGNs）. Methods The mRNA of NR1 subunit of NMDA receptor in modiolus tissues were detected by Real time fluorescence quantitative PCR （FQ-PCR）. NMDA receptor whole-cell currents were recorded using patch clamp in acute isolated SGNs. Results Compared with the control group, salicylate significantly increased the mRNA level of NR1 subunit in SGNs. NMDA of concentrations ranging from 0.1 mM to 10 mM evoked no current in SGNs. NMDA （0. 1mM and 0.5 mM） applied with salicylate （5 mM）, however, induced inward currents （212.6±15.2pA, n=5; 607.9±44.3pA, n=5） in a dose-dependent manner, which could be inhibited by APV. Salicylate alone did not produce any current in SGNs. Conclusion Salicylate increases the expression of NMDA receptors and facilitates the currents mediated by NMDA receptors in SGNs.
基金supported by Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘Objective Glycine acts as a co-agonist for the activation of N-methyl-D-aspartate receptors （NMDARs） by binding to glycine sites, thus potentiating glutamate-elicited responses and inhibiting NMDAR desensitization in a dose-dependent manner. The present study aimed to characterize the glycine-dependent inactivation of NMDARs and to explore its pathophysiological significance. Methods Primary hippocampal cell cultures from embryonic days 17-18 rats were treated with NMDA or NMDA plus glycine. Patch-clamp recording and intracellular Ca 2＋ imaging were performed to test the effects of glycine on NMDA-activated currents and increase of intracellular free Ca 2＋ respectively. Immunofluorescence staining was conducted to examine NR1 internalization. Cell damage was tested with MTT method and lactate dehydrogenase leakage. Results Glycine reduced the peak current and Ca 2＋ influx elicited by NMDA application at concentrations ≥300 μmol/L. This is a novel suppressive influence of glycine on NMDAR function, since it occurs via the NMDAR glycine-binding site, in contrast to the classic suppression, which occurs through the binding of glycine to glycine receptors. The level of membrane NMDARs was measured to evaluate whether internalization was involved. Immunohistochemical labeling showed that incubation with high concentrations of NMDA plus glycine did not change the expression of NMDARs on the cell surface when compared to the expression without glycine; hence the possibility of NMDAR internalization primed by glycine binding was excluded. Conclusion In summary, the novel suppressive effect of glycine on NMDARs was mediated via binding to the glycine site of the NMDAR and not by activation of the strychnine-sensitive glycine-receptor-gated chloride channel or by the internalization of NMDARs. The inhibitory influence of glycine on NMDARs adds a new insight to our knowledge of the complexity of synaptic transmission.
