大鼠骶髓后连合核神经元的分离

To isolate rat sacral dorsal commissural neurons (SDCN). METHODS: Using enzymatic and mechanical dissociation techniques to isolate the neurons and using nystatin perforated patch technique to evaluate their functional state. RESULTS: The isolated neurons exhibited good responses to excitatory and inhibitory amino acids. The responses of SDCN to N-methyl-D-aspartate were markedly potentiated by substance P and trans-1-aminocyclopentane-1,3-dicarboxylate, whereas GABA responses were significantly potentiated by diazepam, pregnenolone, and pentobarbital. CONCLUSION: This preparation provides a satisfactory model for exploring the mechanisms of the SDCN in nociception and antinociception.     

SKF97541抑制大鼠骶髓后联合核神经元

目的研究GABAB受体特异性激动剂SKF97541对骶髓后联合核(SDCN)神经元的作用。方法在大鼠骶段脊髓横切薄片上,利用全细胞膜片钳法记录骶髓后联合核神经元。电流钳记录模式下,观察SKF97541对神经元膜电位和动作电位发放的影响。电压钳模式下,观察谷氨酸能兴奋性突触后电流(EPSCs)对SKF97541处理的变化。结果SKF97541(0.5μmol.L-1)通过作用于GABAB受体,减少SDCN神经元动作电位发放,同时促进细胞膜超极化。SKF97541在电压钳模式下,减少谷氨酸介导的微小EPSCs的频率,但对振幅无影响,提示SKF97541通过作用于突触前GABAB受体抑制谷氨酸释放。突触前刺激引起的突触后电位,也被SKF97541抑制。结论在骶髓后联合核,SKF97541通过作用于突触后GABAB受体,直接抑制神经元的兴奋性和动作电位发放;并通过突触前GABAB受体,抑制谷氨酸的释放。以上结果提示SKF97541的抑制作用可能抑制骶髓后联合核神经元对伤害性信息的传递。     

松果体素抑制大鼠海马神经元甘氨酸激活的全细胞电流

目的研究松果体素对培养的大鼠海马神经元甘氨酸激活的全细胞电流(Igly)的调控。方法在培养的大鼠海马神经元上,采用全细胞膜片钳技术,研究松果体素对甘氨酸激活的全细胞电流的调控。结果松果体素以浓度依赖的方式可逆地抑制Igly,并且这种抑制作用是非竞争性的,松果体素的抑制作用没有特异的亚基选择性。结论松果体素能以非竞争的方式直接抑制甘氨酸受体介导的电流,这种抑制作用可能对海马区域神经网络的兴奋性产生影响。     

辣椒素受体参与骶髓后联合核神经元突触传递

目的研究辣椒素受体对大鼠骶髓后联合核(SDCN)神经元突触传递的影响。方法在脊髓骶段横切薄片上,利用全细胞膜片钳法记录骶髓后联合核神经元谷氨酸能兴奋性突触后电流(EPSCs)和γ-氨基丁酸(GABA)能抑制性突触后电流(IPSCs),比较激动辣椒素受体后上述突触电流的变化;观察激动辣椒素受体对SDCN神经元动作电位发放的影响。结果辣椒素受体被其特异性激动剂辣椒素(1μmol.L-1)激动后,自发EPSCs(sEPSCs)的频率和振幅均有明显增加(P<0.05,n=17)。在河豚毒素(0.5μmol.L-1)存在的条件下,辣椒素明显增加微小EPSCs(mEPSCs)的频率(P<0.01,n=13),但对mEPSCs的振幅无影响(P>0.05,n=13),提示辣椒素的作用在突触前。辣椒素也明显增加动作电位发放(P<0.05,n=19)。上述作用均可被辣椒素受体特异性拮抗剂capsazepine(10μmol.L-1)阻断。辣椒素也增加GABA能的自发IPSCs(sIPSCs)的频率(P<0.05,n=20),但对其不依赖动作电位的微小IPSCs(mIPSCs)的频率或振幅均无作用(P>0.05,n=9)。结论在SDCN,辣椒素受体主要表达于兴奋性突触终末;激动辣椒素受体影响兴奋性和抑制性突触活动,并可能参与痛觉信息在脊髓水平的传递和调制。     

周边γ-氨基丁酸通过GABA_B受体调控骶髓后联合核神经元谷氨酸能突触

目的研究突触周边γ-氨基丁酸(ambient GABA)通过GABAB受体调控骶髓后联合核(SDCN)神经元谷氨酸能突触的机制。方法在急性切取的骶段脊髓薄片上,利用全细胞膜片钳法记录骶髓后联合核神经元谷氨酸能兴奋性突触后电流(EPSCs),将GABAB受体用其特异性受体拮抗剂CGP52432阻断,观察谷氨酸突触终末上的GABAB受体被周边GABA作用的影响。结果在突触后GABAB受体被从胞内阻断的条件下,再灌流CGP52432阻断谷氨酸能突触前GABAB受体,可增加刺激引发的EPSCs(eEPSCs)幅度;改变配对刺激的两个EPSC比率(paired-pulse ratio,PPR),并激发沉默突触(silent synapse)。但CGP52432对微小兴奋性突触后电流(mEPSCs)无影响。结论位于SDCN神经元谷氨酸能突触前的GABAB受体受周边GABA调控。这种影响参与调节谷氨酸释放并可能参与痛觉信息在脊髓水平的传递。     

淫羊藿总黄酮抑制大鼠脊髓背角神经元甘氨酸激活的全细胞电流

目的研究淫羊藿总黄酮对急性分离的大鼠脊髓背角神经元甘氨酸激活的全细胞电流(IGly)的调控。方法在急性分离的大鼠脊髓背角神经元上,采用全细胞膜片钳方法,研究淫羊藿总黄酮对甘氨酸激活的全细胞电流的调控。结果淫羊藿总黄酮呈浓度依赖性地抑制IGly;淫羊藿总黄酮使甘氨酸的浓度-效应曲线平行右移;淫羊藿总黄酮没有改变甘氨酸受体的离子选择性。结论淫羊藿总黄酮对甘氨酸介导的反应产生抑制作用可能是由于降低了甘氨酸与其受体的亲和力。     

腰椎髓核摘除术后椎间隙感染的诊断治疗

目的探讨腰椎髓核摘除术后椎间隙感染的诊断及治疗方法。方法对本院10年来7例腰椎髓核摘除术后椎间隙感染的病例进行回顾性分析。对于早期有迹象表明术后椎间隙感染的患者,治疗要求上绝对卧床,早期静脉联合应用大剂量抗生素,并适当给予激素;2周后没有明显疗效的患者,且腰部症状进行性加重,伴有抽搐及高热等症状或者高热消退后再次出现高热的患者,应尽早行病灶清除及灌洗引流术。结果 7例椎间隙感染患者,非手术治疗4例,手术治疗3例。7例患者均治愈,术后6～12周在腰椎保护下行走。随访6个月～1年,效果优良。结论发现椎间隙有感染的迹象,应尽早治疗,一旦保守治疗效果较差,应立即行病灶清除及灌洗引流术。     

探讨骶管封闭对胶原酶溶核术后的增效作用

目的:探讨骶管封闭对胶原酶溶核术后的增效作用。方法:对20例腰椎间盘突出症(其中中央型7例,单侧型9例,伴椎管狭窄2例,极外侧型1例,游离型l例)行胶原酶溶栓术后,2～7 d内再行骶管注射封闭2次。结果:术后2 wk优良率达95%,1月优良率为90%,3月后优良率为85%,6月后优良率为80%。结论:胶原酶具有特异性溶核作用,适用于单纯性椎间盘突出症,骶管封闭注射主要是镇痛消炎、改善神经的血循环,是溶核术的辅助措施,能提高溶核术的早期疗效。     

24例椎间盘突出髓核摘除术后的护理

目的：探讨腰椎间盘突出症髓核摘除术后的护理措施,总结术后有效的护理经验。方法：回顾性分析2006年1月-2010年12月在我院行髓核摘除手术的24例腰椎间盘突出患者的临床护理资料。结果：24例行髓核摘除手术的腰椎间盘突出患者术后未发生切口感染和椎间隙感染,2例患者术后发生脑脊液漏,经过积极治疗护理后症状消失;在护理人员的指导下,其中两例脑脊液漏患者需卧床7-10天,其余所有患者术后5天在腰围保护下均能顺利下床活动。结论：术后严密观察病情,做好心理护理、并发症的护理,及时、正确的指导功能锻炼,对提高患者预后和生命质量,促进功能恢复有重要意义,     

Potentiation of inhibitory amino acid receptors-mediated responses by lanthanum in rat sacral dorsal commissural neurons

Lanthanum is one of rare earth cations with extremely active chemical property and has been reported to influence neuronal transmitter systems. To date, little attention has been directed towards the sacral dorsal commissural nucleus (SDCN), which serves as a relay of sensory information from the pelvic viscera in the spinal cord. Therefore, the effect of lanthanum on the inhibitory neurotransmitter γ-aminobutyric acid (GABA) and glycine (Gly) responses in neurons acutely dissociated from the rat SDCN was investigated using the nystatin-perforated patch-recording configuration under voltage-clamp conditions. At a holding potential of − 40 mV, La³⁺ reversibly potentiated GABA (3 μM)-activated currents (I_GABA) in a concentration-dependent manner over the concentration range of 10 μM to 30 mM, with the EC₅₀ value of 67.3 ± 16.4 μM. Similarly, La³⁺ reversibly potentiated glycine (10 μM)-activated currents (I_Gly) in a concentration-dependent manner over the concentration range of 1 μM to 1 mM, with the EC₅₀ value of 52.3 ± 10.9 μM. The effects of La³⁺ on I_GABA and I_Gly were voltage-independent. Moreover, both of the potentiations were not use-dependent and were overcome by increasing the concentration of agonist. Our results indicate that La³⁺ potentiates the inhibitory amino acid receptors-mediated responses in SDCN, which may reduce the transmission of the pelvic visceral information. The information provided by this work may help to elucidate the mechanisms and effects of lanthanum on brain functions.     

Dual effects of pentobarbital on rat sacral dorsal commissural neurons in vitro

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5-HT potentiation of the GABAA response in the rat sacral dorsal commissural neurones

1. The modulatory effect of 5-hydroxytryptamine (5-HT) on the γ-aminobutyric acid_A (GABA_A) response was investigated in the neurones freshly dissociated from the rat sacral dorsal commissural nucleus (SDCN) using the nystatin perforated patch recording configuration under the voltage-clamp conditions.
2. 5-HT potentiated GABA-induced Cl⁻ current (I_GABA) without affecting the reversal potential of I_GABA and the apparent affinity of GABA to its receptor.
3. α-Methyl-5-HT mimicked the potentiation effect of 5-HT on I_GABA while ketanserine blocked it. 1-Oleoyl-2-acetyl-glycerol (OAG) potentiated I_GABA, and the effect of 5-HT on I_GABA was occluded by OAG pretreatment. In the presence of chelerythrine, 5-HT failed to potentiate I_GABA, suggesting that protein kinase C (PKC) is involved in the pathway through which the activation of the 5-HT₂ receptor potentiates the I_GABA.
4. The facilitatory effect of 5-HT on I_GABA remained in the presence of BAPTA-AM. LiCl also had no effect on 5-HT-induced potentiation of I_GABA.
5. H-89, genistein, okadaic acid and pervanadate all had no effects on 5-HT potentiation of I_GABA. Pertussis toxin treatment for 6–8 h did not block the facilitatory effect of 5-HT on I_GABA.
6. The present results show that GABA_A receptor in the rat SDCN could be modulated in situ by 5-HT, one of the major transmitters involved in the supraspinal control of nociception, and that the phosphorylation of GABA_A receptor by PKC may be sufficient to support such modulation. The results also strongly support the hypothesis that the cotransmission by 5-HT and GABA has an important role in the spinal cord.

     

龙血素B抑制大鼠背根神经节细胞辣椒素诱发的电流反应

目的探讨龙血素B对大鼠背根神经节细胞辣椒素诱发的辣椒素受体电流的影响。方法采用全细胞膜片钳技术在急性分离的大鼠背根神经节细胞上观察龙血素B对辣椒素诱发的辣椒素受体电流的影响。结果①在-60mV的钳制电位下,辣椒素受体拮抗剂辣椒卓平可以完全抑制辣椒素受体电流;②不同浓度的龙血素B溶液对辣椒素诱发的受体电流具有浓度依赖的抑制作用;2.0、4.0、8.0和16.0μmol.L-1的龙血素B溶液对辣椒素诱发的受体电流峰值的抑制率分别为15.36%±2.12%、36.41%±2.43%、76.26%±2.16%和96.69%±3.21%(n=10,P<0.05),半数抑制浓度(IC50)为4.9μmol.L-1,Hill系数为2.29。结论龙血素B可以明显抑制辣椒素诱发的辣椒素受体电流,影响痛觉信息的传入,这可能是以龙血素B为重要成分的中药血竭产生镇痛作用的机制之一。