AN INVITRO MATURE SPINAL-CORD PREPARATION FROM THE RAT
AN INVITRO MATURE SPINAL-CORD PREPARATION FROM THE RAT
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DOI：
10.1016/0028-3908(88)90138-4
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发表时间：
1988-05-01
影响因子：
4.7
通讯作者：
BEVAN, P
中科院分区：
文献类型：
--
作者：
LONG, SK;EVANS, RH;BEVAN, P
描述了从成熟（180-300 g体重）大鼠制备保持在体外的分离的半切脊髓制备物。骶骨和尾骨段（S2-Co 1）通过电刺激背根产生一致的腹根反射（DR-VRP）。腹根反射中最快成分的平均潜伏期和振幅，在25 ° C。C，为1.6毫秒±。0.4 SE平均值和8.2 mV ±。0.9分别为SE平均值（28份制备液）。该组分对NMDA拮抗剂2-氨基-5-膦酸戊酸酯（AP 5）具有抗性，但被犬尿氨酸显著抑制。一个缓慢的组成部分的腹根反射，这是敏感的AP 5增强和自发的AP 5敏感的突触电位敏感的AP 5出现在镁离子的情况下。兴奋性氨基酸L-天冬氨酸、L-谷氨酸、N-甲基-D-天冬氨酸（NMDA）、红藻氨酸和使君子酸在前根产生剂量依赖性的去极化反应。相对去极化效力。+-。相对于L-谷氨酸= 1，NMDA、红藻氨酸和使君子酸的SE平均值（N）为96 ± 1。30（6），234 .+-. 57（6）和145 .+-。40（5），分别。这些特性，除了减少突触反应的潜伏期外，与先前描述的来自未成熟动物的制剂相似。然而，成熟的制剂更容易选择性地激活高阈值和低阈值初级传入。
The preparation of an isolated hemisected spinal cord preparation, maintained in vitro, from mature (180-300 g body weight) rats is described. Sacral and coccygeal segments (S2-Co1) gave consistent ventral root reflexes (DR-VRP) from electrical stimulation of dorsal roots. The mean latency and amplitude of the fastest component in the ventral root reflex, at 25.degree. C, were 1.6 msec .+-. 0.4 SE mean and 8.2 mV .+-. 0.9 SE mean, respectively (28 preparations). This component was resistant to the NMDA antagonist, 2-amino-5-phosphonopentanoate (AP5) but was depressed markedly by kynurenate. A slow component of the ventral root reflex, which was sensitive to AP5 was enhanced and spontaneous AP5-sensitive synaptic potentials sensitive to AP5 appeared in the absence of magnesium ions. The excitant amino acids L-aspartate, L-glutamate, N-methyl-D-aspartate (NMDA), kainate and quisqualate, produced dose-dependent depolarizaing responses in the ventral roots. The relative depolarizing potencies .+-. SE mean (N) of NMDA, kainate and quisqualate, relative to L-glutamate = 1, were 96 .+-. 30 (6), 234 .+-. 57 (6) and 145 .+-. 40 (5), respectively. These properties, apart from reduced latency of synaptic responses, are similar to those described previously for preparations from immature animals. However, it will be easier with the mature preparation to selectively activate high and low threshold primary afferents.