To investigate the effect of intedeukin-1β （IL-1β） on IA and IK currents in cultured murine trigeminal ganglion （TG） neurons, whole-cell patch clamp technique was used to record the IA and IK currents before and...To investigate the effect of intedeukin-1β （IL-1β） on IA and IK currents in cultured murine trigeminal ganglion （TG） neurons, whole-cell patch clamp technique was used to record the IA and IK currents before and after 20 ng/mL IL-1β perfusion. Our results showed that 20 ng/mL IL-1β inhibited IA currents （18.3±10.7）% （n=6, P〈0.05）. IL-1β at 20 ng/mL had no effect on G-V curve of IA but moved the H-infinity curve V0.5 from -36.6±6. 1 mV to-42.4±5.2 mV （n=5, P〈0.01）. However, 20 ng/mL IL-1β had effect on neither the amplitude nor the G-V curve of IK. IL-1β was found to selectively inhibit IA current in TG neurons and the effect may contribute to hyperalgesia under various inflammatory conditions.展开更多
This paper uses spatial panel data models to analyze regional growth in China.Controlling for fixed-effects allows us to disentangle the effect of spatial dependence from that of spatial heterogeneity and omitted vari...This paper uses spatial panel data models to analyze regional growth in China.Controlling for fixed-effects allows us to disentangle the effect of spatial dependence from that of spatial heterogeneity and omitted variable to investigate the regional convergence process within the country.展开更多
The different effects of capsaicin on IA and IK currents in pain-conduct neurons of trigeminal ganglia （TG） were investigated. In cultured TG neurons of rats, whole-cell patch clamp techniques were used to record th...The different effects of capsaicin on IA and IK currents in pain-conduct neurons of trigeminal ganglia （TG） were investigated. In cultured TG neurons of rats, whole-cell patch clamp techniques were used to record the IA and IK before and after capsaicin perfused. Results revealed that 1 μmol/L capsaicin could inhibit the amplitude of IA by 48.2% （n= 10, P〈0.05）, but had no inhib- itory effect on IK （n=7, P〈0.05）. Ten μmol/L capsaicin could significantly inhibit the amplitude of IA by 93.2 % （n=8, P〈0.01）, but only slightly inhibit the amplitude of IK by 13.2 % （n=7, P〈0.05）. Neither 1 μmol/L nor 10 μmol/L capsaicin had effects on the active curve of IA and IK. It was concluded that capsaicin could selectively inhibit the IA current, and this effect might involve in the analgesic mechanisms of capsaicin.展开更多
Cyproheptadine （CPH）, a first-generation anti- histamine, enhances the delayed rectifier outward K＋ current （IK） in mouse cortical neurons through a sigma-1 receptor-mediated protein kinase A pathway. In this stu...Cyproheptadine （CPH）, a first-generation anti- histamine, enhances the delayed rectifier outward K＋ current （IK） in mouse cortical neurons through a sigma-1 receptor-mediated protein kinase A pathway. In this study, we aimed to determine the effects of CPH on neuronal excitability in current-clamped pyramidal neurons in mouse medial prefrontal cortex slices. CPH （10 μmol/L） significantly reduced the current density required to generate action potentials （APs） and increased the instan- taneous frequency evoked by a depolarizing current. CPH also depolarized the resting membrane potential （RMP）, decreased the delay time to elicit an AP, and reduced the spike threshold potential. This effect of CPH was mim- icked by a sigma-1 receptor agonist and eliminated by an antagonist. Application of tetraethylammonium （TEA） to block IK channels hyperpolarized the RMP and reduced the instantaneous frequency of APs. TEA eliminated the effects of CPH on AP frequency and delay time, but had no effect on spike threshold or RMP. The current-voltage relationship showed that CPH increased the membrane depolarization in response to positive current pulses and hyperpolarization in response to negative current pulses, suggesting that other types of membrane ion channels might also be affected by CPH. These results suggest that CPH increases the excitability of medial prefrontal cortex neurons by regulating TEA-sensitive IK channels as well as other TEA-insensitive K＋ channels, probably ID and inward-rectifier Kir channels. This effect of CPH may explain its apparent clinical efficacy as an antidepressant and antipsychotic.展开更多
基金The project was supported by a grant from the National Natural Sciences Foundation of China (No. 30271500)
文摘To investigate the effect of intedeukin-1β （IL-1β） on IA and IK currents in cultured murine trigeminal ganglion （TG） neurons, whole-cell patch clamp technique was used to record the IA and IK currents before and after 20 ng/mL IL-1β perfusion. Our results showed that 20 ng/mL IL-1β inhibited IA currents （18.3±10.7）% （n=6, P〈0.05）. IL-1β at 20 ng/mL had no effect on G-V curve of IA but moved the H-infinity curve V0.5 from -36.6±6. 1 mV to-42.4±5.2 mV （n=5, P〈0.01）. However, 20 ng/mL IL-1β had effect on neither the amplitude nor the G-V curve of IK. IL-1β was found to selectively inhibit IA current in TG neurons and the effect may contribute to hyperalgesia under various inflammatory conditions.
文摘This paper uses spatial panel data models to analyze regional growth in China.Controlling for fixed-effects allows us to disentangle the effect of spatial dependence from that of spatial heterogeneity and omitted variable to investigate the regional convergence process within the country.
文摘The different effects of capsaicin on IA and IK currents in pain-conduct neurons of trigeminal ganglia （TG） were investigated. In cultured TG neurons of rats, whole-cell patch clamp techniques were used to record the IA and IK before and after capsaicin perfused. Results revealed that 1 μmol/L capsaicin could inhibit the amplitude of IA by 48.2% （n= 10, P〈0.05）, but had no inhib- itory effect on IK （n=7, P〈0.05）. Ten μmol/L capsaicin could significantly inhibit the amplitude of IA by 93.2 % （n=8, P〈0.01）, but only slightly inhibit the amplitude of IK by 13.2 % （n=7, P〈0.05）. Neither 1 μmol/L nor 10 μmol/L capsaicin had effects on the active curve of IA and IK. It was concluded that capsaicin could selectively inhibit the IA current, and this effect might involve in the analgesic mechanisms of capsaicin.
基金supported by the National Natural Science Foundation of China(31370827)the Shanghai Leading Academic Discipline Project [B111]
文摘Cyproheptadine （CPH）, a first-generation anti- histamine, enhances the delayed rectifier outward K＋ current （IK） in mouse cortical neurons through a sigma-1 receptor-mediated protein kinase A pathway. In this study, we aimed to determine the effects of CPH on neuronal excitability in current-clamped pyramidal neurons in mouse medial prefrontal cortex slices. CPH （10 μmol/L） significantly reduced the current density required to generate action potentials （APs） and increased the instan- taneous frequency evoked by a depolarizing current. CPH also depolarized the resting membrane potential （RMP）, decreased the delay time to elicit an AP, and reduced the spike threshold potential. This effect of CPH was mim- icked by a sigma-1 receptor agonist and eliminated by an antagonist. Application of tetraethylammonium （TEA） to block IK channels hyperpolarized the RMP and reduced the instantaneous frequency of APs. TEA eliminated the effects of CPH on AP frequency and delay time, but had no effect on spike threshold or RMP. The current-voltage relationship showed that CPH increased the membrane depolarization in response to positive current pulses and hyperpolarization in response to negative current pulses, suggesting that other types of membrane ion channels might also be affected by CPH. These results suggest that CPH increases the excitability of medial prefrontal cortex neurons by regulating TEA-sensitive IK channels as well as other TEA-insensitive K＋ channels, probably ID and inward-rectifier Kir channels. This effect of CPH may explain its apparent clinical efficacy as an antidepressant and antipsychotic.
