Effects of Hypoxia on the Ventral Root Motor-Evoked potential in the In Vitro Spinal Cord Preparation

缺氧对体外脊髓制备中腹根运动诱发电位的影响

• 批准号: 07671571
• 负责人: MURAKAMI Masazumi
• 金额: $ 1.41万
• 依托单位: Chiba University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07671571/
• 关键词: Motor-Evoked Potential; Hypoxia; Inhibitory Neurotransmitter; Interneuron; Glucose; 脊髄運動誘発電位; in vitro頚髄標本; シナプス伝達; グルコース

We studied the effects of hypoxia on synaptic transmission of motor pathway in spinal cord using in vitro preparations.The cervical spinal cords of neonatal rats were isolated and superfused with oxygenated artificial cerebrospinal fluid (aCSF) at room temperature. The ventral root motor evoked potentials (VR-MEP) were recorded from C7 ventral roots in responce to stimulation to the ventrolateral funiculus (VLF) at Cl.VR-MEP consisted of the early and the late components. The replacement of Ca^<2+> in aCSF by Mn^<2+> reversibly blocked both components supporting them to be trans-synaptic origin. Within 10-40 min of superfusion with hypoxic aCSF,the amplitudes of both components in VR-MEP increased to 130-140% of the control, and then declined progressively to 30% in 90 min. The latency of the early component was prolonged during hypoxia. After 60 min rexygenation, VR-MEP amplitudes recovered to 80-95% with full restoration of the latency.The application of inhibitory amino acid antagonists strychnine (2muM) and picrotoxin (1muM) abolished the augmentation of VR-MEP amplitudes observed in the early phase of hypoxia. The present results suggested that in the early phase of hypoxia amplitudes of VR-MEP were increased because of selective depression of inhibitory synaptic transmission.

采用体外制备方法，研究缺氧对脊髓运动通路突触传递的影响。分离新生大鼠颈脊髓，在常温下用含氧人工脑脊液(ACSF)进行灌流。记录C7腹根运动诱发电位(VR-MEP)，由早、晚期两部分组成。用Mn^&lt；2+&gt；替换ACSF中的Ca^&lt；2+&gt；可逆性地阻断了支持它们是跨突触起源的两个成分。低氧ACSF灌流10~40min时，VR-MEP中两个成分的波幅均升高至对照组的130~140%，90min后逐渐下降至30%。低氧时早期成分潜伏期延长。复氧60min后，VR-MEP波幅恢复至80-95%，潜伏期完全恢复，应用抑制性氨基酸拮抗剂士的宁(2muM)和印防己毒素(1muM)可消除缺氧早期VR-MEP波幅的增加。结果提示，在低氧早期，由于选择性抑制抑制性突触传递，VR-MEP波幅增加。

项目成果

H.Ataka,et al: "Effests of Hypoxia on the Ventral Root Motor-Evoked Potential in the In Vitro Spinal Cord Preparation" Spine. 21・18. 2095-2100 (1996)

H.Ataka 等人：“体外脊髓准备中缺氧对腹根运动诱发电位的影响”21・18（1996 年）。

H.Ataka, et al: "Effects of Hypoxia and Roles of Inhibitory Neurotransmitters on Motor-Evoked Potentials in the In Vitro Neonatal Rat Spinal Cord Preparation" J.Electrodiag.of the Spinal Cord. Vol 17. 5-8 (1995)

H.Ataka 等人：“缺氧的影响和抑制性神经递质对体外新生大鼠脊髓准备中运动诱发电位的作用”J.Electrodiag.of the Spinal Cord。

H.Ataka, et al: "Effects of Hypoxia on the Ventral Root Motor-Evoked Potential in the In Vitro Spinal Cord Preparation" Spine. Vol 21, No 18. 2095-2100 (1996)

H.Ataka 等人：“缺氧对体外脊髓准备中腹根运动诱发电位的影响”脊柱。