Spread of epileptiform activity in the immature rat neocortex studied with voltage-sensitive dyes and laser scanning microscopy.
Spread of epileptiform activity in the immature rat neocortex studied with voltage-sensitive dyes and laser scanning microscopy.
复制标题
使用电压敏感染料和激光扫描显微镜研究未成熟大鼠新皮质中癫痫样活动的传播。
DOI：
10.1152/jn.1994.72.4.1756
复制
发表时间：
1994
影响因子：
2.5
通讯作者：
tenBruggencate,G
中科院分区：
文献类型：
--
作者：
Sutor,B;Hablitz,JJ;Rucker,F;tenBruggencate,G
1.成年大鼠和出生后3-29天的大鼠（PN 3-29）用于制备额叶新皮层的体外切片。癫痫样活动诱导浴应用γ-氨基丁酸-A（GABAA）受体拮抗剂荷包牡丹碱或印防己毒素。2.电压敏感染料RH 414和激光扫描显微镜被用于与癫痫样活动相关的膜电位变化的多位点光学记录。光信号进行了比较，同时测量细胞外场电位。3.在实验持续时间（2-4小时）内可以可靠地记录光信号。细胞外记录惊厥诱导的阵发性去极化位移（PDS）的切片染色与RH 414与未染色切片中获得的。响应于细胞外钙的减少、河豚毒素（TTX）的添加或兴奋性氨基酸受体拮抗剂的应用的染料信号的变化表明荧光变化与癫痫样活动的已建立的电生理测量良好相关。4.在来自成年动物的切片中，在所有记录部位观察到染料信号。具有最短潜伏期的反应总是发生在刺激部位，并且活动在垂直和水平方向上迅速传播。垂直方向的扩散速度明显快于水平方向。5.在PN 3-9动物的切片中，癫痫样活动不存在或仅微弱表达。活动主要是在上皮层检测。6.在PN 10-19动物切片的所有测量点观察到染料信号。在这个年龄组中，峰值振幅随着活动从下到上皮层的扩散而增加。垂直和水平方向的传播速度无显著差异。自发性癫痫样活动在PN 10-19年龄组中发生率较高，与自发性癫痫样事件相关的信号在上层最大。7.在PN 10-19年龄组中，光信号的特征在于PDS放电叠加在持续反应上的重复发生。持续反应的幅度随着距离刺激部位的距离增加而降低。对激光的分析表明，在扫描区域内的多个部位产生了叠加的PDS样事件。PN 10-19动物切片的幅度和上升速率最大。这些值随着持续的发展而下降。（400字处截断摘要）
1. Adult rats and rats with a postnatal age of 3–29 days (PN 3–29) were used for the preparation of in vitro slices of the frontal neocortex. Epileptiform activity was induced by bath application of the gamma-aminobutyric acid-A (GABAA) receptor antagonists bicuculline or picrotoxin. 2. The voltage-sensitive dye RH 414 and a laser scanning microscope were used for multiple-site optical recordings of membrane potential changes associated with epileptiform activity. Optical signals were compared with simultaneously measured extra-cellular field potentials. 3. Optical signals could be reliably recorded for the duration of the experiments (2–4 h). Extracellular recordings of convulsant-induced paroxysmal depolarizing shifts (PDSs) in slices stained with RH 414 were comparable with those obtained in unstained slices. Changes in dye signals in response to reductions in extracellular calcium, addition of tetrodotoxin (TTX), or application of excitatory amino acid receptor antagonists indicate that the fluorescence changes correlate well with established electrophysiological measures of epileptiform activity. 4. In slices from adult animals, dye signals were observed at all recording sites. The response with the shortest latency occurred invariably at the site of stimulation, and activity spread rapidly in both vertical and horizontal directions. Spread was significantly faster in the vertical than in the horizontal direction. 5. Epileptiform activity was absent or only weakly expressed in slices from PN 3-9 animals. Activity was detectable predominantly in upper cortical layers. 6. Dye signals were observed at all measurement points in slices from PN 10–19 animals. In this age group, peak amplitude increased with spread of activity from lower to upper cortical layers. There was no significant difference between the speed of propagation in the vertical and in the horizontal directions. Spontaneous epileptiform activity occurred at a high rate in the PN 10–19 age group, and signals associated with spontaneous epileptiform events were largest in upper layers. 7. In the PN 10–19 age group, optical signals were characterized by the repetitive occurrence of PDS discharges superimposed on a sustained response. The amplitude of the sustained response decreased with increasing distance from the site of stimulation. Analysis of the latencies revealed that the superimposed PDS-like events were generated at multiple sites within the scanning area. Amplitude and rate of rise were largest in slices from PN 10–19 animals. These values declined with ongoing development.(ABSTRACT TRUNCATED AT 400 WORDS)