目的观察异丙酚对小鼠鼠海马锥体神经元膜特性和突触后电流的影响。方法用冰冻切片的方法将C57小鼠海马半脑切成300μm厚度。运用全细胞膜片钳技术记录海马锥体神经元在异丙酚作用前后动作电位反应、I-V曲线及突触后电流反应后变化情况...目的观察异丙酚对小鼠鼠海马锥体神经元膜特性和突触后电流的影响。方法用冰冻切片的方法将C57小鼠海马半脑切成300μm厚度。运用全细胞膜片钳技术记录海马锥体神经元在异丙酚作用前后动作电位反应、I-V曲线及突触后电流反应后变化情况。结果异丙酚明显减少不同刺激强度下胞体动作电位产生的个数,加入异丙酚后使锥体细胞动作电位发放个数由5±3个降至2±1个(P<0.01),而对动作电位幅度无显著影响。异丙酚可改变海马锥体神经元对兴奋性电压刺激的I-V曲线平台期反应,使最大电流幅度由1647.63±124.02 p A增加至2955.08±119.10 p A(P<0.01)。异丙酚可降低锥体神经元突触后电流,加入异丙酚前为146.5±25.89 p A,加入异丙酚后为72.8±18.71 p A(P<0.01),20 min洗脱异丙酚后电流幅度恢复至132.1±30.2 p A(P<0.01)。结论异丙酚可降低海马锥体神经元动作电位发放数,改变I-V曲线兴奋性平台期反应和可逆地降低神经元突触后电流反应。展开更多
OBJECTIVE To explore the protective effects and mechanisms of Ginsenoside Rg1(Rg1) on H_2O_2-induced hippocampal neurons aging in vitro.METHODS The primary culture hippo.campal neurons(7 d) were randomly placed into s...OBJECTIVE To explore the protective effects and mechanisms of Ginsenoside Rg1(Rg1) on H_2O_2-induced hippocampal neurons aging in vitro.METHODS The primary culture hippo.campal neurons(7 d) were randomly placed into six groups:normal control group,H_2O_2(200 μM) treat.ment group,and H_2O_2+Rg1(1,5 and 10μM) groups.The neurons were with Rg1(1,5 and 10 μmol·L^(-1))for 6 h.H_2O_2(200 μmol · L-1) was added to the medium and incubate for 18 h.The Dihydroethidium(DHE) staining was performed for ROS production assessment.The LDH release and Hoechst 33258 were performed to examine the neuronal damage and apoptosis.The immunoblot was used to deter.mine the expression of β-Gal,NOX2,p22 phox,p47 phox,NLRP-1,ASC and Caspase-1 in hippocampal neurons.The ELISA was performed to detect the levels of IL-1β and IL-18 released in the supernatant in hippocampal neurons.RESULTS Rg1(5 and 10 μmol·L^(-1)) significantly reduced the ROS production,attenuated H_2O_2-induced neuronal damage and apoptosis(P<0.05,P<0.01).The immunoblot results showed that Rg1(5 and 10 μmol·L^(-1)) treatment significantly decreased the expression of β-Gal,NOX2,p22 phox,p47 phox,NLRP-1,ASC and Caspase-1 in hippocampal neurons(P<0.05,P<0.01).Additionally,Rg1(5 and 10 μmol·L^(-1)) treatment significantly decreased IL-1β and IL-18 release in the supernatant.CONCLUSION The protective effect of Rg1 in H_2O_2-induced hippocampal neurons aging may be due to inhibit NOX2-NLRP1 activation.展开更多
HCMV is a major cause of congenital brain disease in humans, and its neuropathogenesis is not yet fully understood. The objective of the present study is to investigate the effect of human cytomegalovirus (HCMV) infec...HCMV is a major cause of congenital brain disease in humans, and its neuropathogenesis is not yet fully understood. The objective of the present study is to investigate the effect of human cytomegalovirus (HCMV) infection on human hippocampus neural precursor cell (NPCs) differentiation in vitro. Fetal hippocampus tissue was dissociated mechanically and then cultured in proliferation medium with EGF and bFGF. The identification and purity of the NPCs were confirmed by using immunofluorescence to detect the expression of the NPCs marker-Nestin. To drive NPCs differentiation, bFGF and EGF were withdrawn from the medium and replaced with FBS (10%). HCMV AD169 (MOI=5) was added into the differentiation medium at the onset of the differentiation. After 7 days of differentiation, in order to confirm whether NPCs are permissive for HCMV infection, immunofluorescence was used to stain for the presence of immediate early (IE) and late (pp65) HCMV proteins in the infected cells. The effects of HCMV infection on NPCs’ differentiation was observed by detecting the ratio of nestin and GFAP positive cells with confocal microscopy and immunofluorescence. The data showed that 95%±8% of the cells (passage 4-8) cultured were Nestin positive which suggested that majority of the cells were NPCs. On day 7 postinfection, most of the infected cells were IE and PP65 positive. The percentage of Nestin-positive cells were 93%±10% and 50%±19% (t=6.03, p<0.01) and those of GFAP-positive cells were 55±17% and 81%±11% (t=3.77, p<0.01) in HCMV treated and control groups respectively. These findings indicate that NPCs are HCMV permissive cells and HCMV (AD 169) infection suppresses the differentiation of Hippocampus-genetic human NPCs into astrocytes. These effects may provide part of the explanation for the abnormalities in brain development associated with congenital HCMV infection.展开更多
Objective: To clarify the firing characteristics of the hippocampal pyramidal cells and in-terneurons in the auditory discrimination cognition. Methods: Thirteen guinea pigs were studied by the paired (active cognitio...Objective: To clarify the firing characteristics of the hippocampal pyramidal cells and in-terneurons in the auditory discrimination cognition. Methods: Thirteen guinea pigs were studied by the paired (active cognition group. n=10) or unpaired (passive cognition group. n = 3) training with 1 kHz (CS+)and 500 Hz tones (CS- ) and the air puff (US) applied 250 ms after the CS+ onset. Results: In active group. 32 pyramidal cells showed exciting response to the CS+ tone. 16 cells inhibited response and 4 cells revealed no response to the high frequency tone and 18 interneurons almost unchanged. In passive group, the pyramidal cells responded to the tone casually and 10 out of the 13 interneurons remained invariably. Conclusion: The result suggests that the pyramidal cells play a major role in coding auditory information by the networks, and the interneuons may modulate it via forward and feedback.展开更多
Objective: To study the rapid effect of glucocorticoids (GCs) on NMDA receptor activity in hippocampal neurons in stress and to elucidate its underlying probable membrane mechanisms. Methods: Whole-cell patch-clamp re...Objective: To study the rapid effect of glucocorticoids (GCs) on NMDA receptor activity in hippocampal neurons in stress and to elucidate its underlying probable membrane mechanisms. Methods: Whole-cell patch-clamp recording was used to assess the effect of stress concentration corticosterone (B) on the responses of cultured hippocampal neurons to glutamate and NMDA (N-methy-D-asparatic acid). To make clear the target of B, intracellular dialysis of B(10 μmol/L)through patch pipette and extracellular application of bovine serum albumin-conjugated corticosterone(B-BSA, 10 μmol/L)were carried out to observe their influence on peak amplitude of NMDA-evoked current. Results: B had a rapid, reversible and inhibitory effect on peak amplitude of GLU- or NMDA-evoked current in cultured hippocampal neurons. Furthermore, B-BSA had the inhibitory effect on INMDA as that of B, but intracellularly dialyzed B had no significant effect on I NMDA. Conclusion: These results suggest that under the condition of stress, GCs may rapidly, negatively regulate excitatory synaptic receptors-glutamate receptors (GluRs), especially NMDA receptor (NMDAR) in central nervous system, which is mediated by rapid membrane mechanisms, but not by classical, genomic mechanisms.展开更多
文摘目的观察异丙酚对小鼠鼠海马锥体神经元膜特性和突触后电流的影响。方法用冰冻切片的方法将C57小鼠海马半脑切成300μm厚度。运用全细胞膜片钳技术记录海马锥体神经元在异丙酚作用前后动作电位反应、I-V曲线及突触后电流反应后变化情况。结果异丙酚明显减少不同刺激强度下胞体动作电位产生的个数,加入异丙酚后使锥体细胞动作电位发放个数由5±3个降至2±1个(P<0.01),而对动作电位幅度无显著影响。异丙酚可改变海马锥体神经元对兴奋性电压刺激的I-V曲线平台期反应,使最大电流幅度由1647.63±124.02 p A增加至2955.08±119.10 p A(P<0.01)。异丙酚可降低锥体神经元突触后电流,加入异丙酚前为146.5±25.89 p A,加入异丙酚后为72.8±18.71 p A(P<0.01),20 min洗脱异丙酚后电流幅度恢复至132.1±30.2 p A(P<0.01)。结论异丙酚可降低海马锥体神经元动作电位发放数,改变I-V曲线兴奋性平台期反应和可逆地降低神经元突触后电流反应。
基金supported by National Natural Science Foundation of China(8167138481371329)
文摘OBJECTIVE To explore the protective effects and mechanisms of Ginsenoside Rg1(Rg1) on H_2O_2-induced hippocampal neurons aging in vitro.METHODS The primary culture hippo.campal neurons(7 d) were randomly placed into six groups:normal control group,H_2O_2(200 μM) treat.ment group,and H_2O_2+Rg1(1,5 and 10μM) groups.The neurons were with Rg1(1,5 and 10 μmol·L^(-1))for 6 h.H_2O_2(200 μmol · L-1) was added to the medium and incubate for 18 h.The Dihydroethidium(DHE) staining was performed for ROS production assessment.The LDH release and Hoechst 33258 were performed to examine the neuronal damage and apoptosis.The immunoblot was used to deter.mine the expression of β-Gal,NOX2,p22 phox,p47 phox,NLRP-1,ASC and Caspase-1 in hippocampal neurons.The ELISA was performed to detect the levels of IL-1β and IL-18 released in the supernatant in hippocampal neurons.RESULTS Rg1(5 and 10 μmol·L^(-1)) significantly reduced the ROS production,attenuated H_2O_2-induced neuronal damage and apoptosis(P<0.05,P<0.01).The immunoblot results showed that Rg1(5 and 10 μmol·L^(-1)) treatment significantly decreased the expression of β-Gal,NOX2,p22 phox,p47 phox,NLRP-1,ASC and Caspase-1 in hippocampal neurons(P<0.05,P<0.01).Additionally,Rg1(5 and 10 μmol·L^(-1)) treatment significantly decreased IL-1β and IL-18 release in the supernatant.CONCLUSION The protective effect of Rg1 in H_2O_2-induced hippocampal neurons aging may be due to inhibit NOX2-NLRP1 activation.
基金National Natural Science Foundation ofChina (30770105)Qingdao Technology Project (08-1-3-30-jch) Mt. Tai Scholar Construction Engineering Special Foundation of Shandong province, China.
文摘HCMV is a major cause of congenital brain disease in humans, and its neuropathogenesis is not yet fully understood. The objective of the present study is to investigate the effect of human cytomegalovirus (HCMV) infection on human hippocampus neural precursor cell (NPCs) differentiation in vitro. Fetal hippocampus tissue was dissociated mechanically and then cultured in proliferation medium with EGF and bFGF. The identification and purity of the NPCs were confirmed by using immunofluorescence to detect the expression of the NPCs marker-Nestin. To drive NPCs differentiation, bFGF and EGF were withdrawn from the medium and replaced with FBS (10%). HCMV AD169 (MOI=5) was added into the differentiation medium at the onset of the differentiation. After 7 days of differentiation, in order to confirm whether NPCs are permissive for HCMV infection, immunofluorescence was used to stain for the presence of immediate early (IE) and late (pp65) HCMV proteins in the infected cells. The effects of HCMV infection on NPCs’ differentiation was observed by detecting the ratio of nestin and GFAP positive cells with confocal microscopy and immunofluorescence. The data showed that 95%±8% of the cells (passage 4-8) cultured were Nestin positive which suggested that majority of the cells were NPCs. On day 7 postinfection, most of the infected cells were IE and PP65 positive. The percentage of Nestin-positive cells were 93%±10% and 50%±19% (t=6.03, p<0.01) and those of GFAP-positive cells were 55±17% and 81%±11% (t=3.77, p<0.01) in HCMV treated and control groups respectively. These findings indicate that NPCs are HCMV permissive cells and HCMV (AD 169) infection suppresses the differentiation of Hippocampus-genetic human NPCs into astrocytes. These effects may provide part of the explanation for the abnormalities in brain development associated with congenital HCMV infection.
文摘Objective: To clarify the firing characteristics of the hippocampal pyramidal cells and in-terneurons in the auditory discrimination cognition. Methods: Thirteen guinea pigs were studied by the paired (active cognition group. n=10) or unpaired (passive cognition group. n = 3) training with 1 kHz (CS+)and 500 Hz tones (CS- ) and the air puff (US) applied 250 ms after the CS+ onset. Results: In active group. 32 pyramidal cells showed exciting response to the CS+ tone. 16 cells inhibited response and 4 cells revealed no response to the high frequency tone and 18 interneurons almost unchanged. In passive group, the pyramidal cells responded to the tone casually and 10 out of the 13 interneurons remained invariably. Conclusion: The result suggests that the pyramidal cells play a major role in coding auditory information by the networks, and the interneuons may modulate it via forward and feedback.
文摘Objective: To study the rapid effect of glucocorticoids (GCs) on NMDA receptor activity in hippocampal neurons in stress and to elucidate its underlying probable membrane mechanisms. Methods: Whole-cell patch-clamp recording was used to assess the effect of stress concentration corticosterone (B) on the responses of cultured hippocampal neurons to glutamate and NMDA (N-methy-D-asparatic acid). To make clear the target of B, intracellular dialysis of B(10 μmol/L)through patch pipette and extracellular application of bovine serum albumin-conjugated corticosterone(B-BSA, 10 μmol/L)were carried out to observe their influence on peak amplitude of NMDA-evoked current. Results: B had a rapid, reversible and inhibitory effect on peak amplitude of GLU- or NMDA-evoked current in cultured hippocampal neurons. Furthermore, B-BSA had the inhibitory effect on INMDA as that of B, but intracellularly dialyzed B had no significant effect on I NMDA. Conclusion: These results suggest that under the condition of stress, GCs may rapidly, negatively regulate excitatory synaptic receptors-glutamate receptors (GluRs), especially NMDA receptor (NMDAR) in central nervous system, which is mediated by rapid membrane mechanisms, but not by classical, genomic mechanisms.
