Optical mapping of early embryonic expressions of Mg(2+)-/APV-sensitive components of vagal glutaminergic EPSPs in the chick brainstem
Optical mapping of early embryonic expressions of Mg(2+)-/APV-sensitive components of vagal glutaminergic EPSPs in the chick brainstem
复制标题
雏鸡脑干中迷走谷氨酰胺能 EPSP 的 Mg(2 )-/APV 敏感成分早期胚胎表达的光学图谱
作者：
Y. Momose;T. Sakai;A. Hirota;K. Sato;K. Kamino
使用电压敏感染料(NK2761)和12×12元光电二极管阵列，多点光学记录跨膜电压活动，以监测6-9天胚胎脑组织切片的神经反应。在制备过程中，对迷走神经施加一个简短的方形电流脉冲，同时记录了多个部位的跨膜电压相关光学反应。在6天龄胚胎的制备中，在含有0.5 mM镁离子的正常浴液中，通常只检测到与动作电位相关的棘状光信号。然而，在无镁(2+)的洗浴介质中，在一些准备材料的多个位点上，诱发了兴奋性突触后电位相关的慢信号，这些慢信号被DL-2-氨基-5-膦-戊酸(2-APV)所阻断。这些结果表明NMDA受体介导的兴奋性突触后电位可能在胚胎中表达。在正常的浴液中，通常从7-9天胚胎的测试样品中检测到缓慢的信号。在无镁浴介质中，慢信号的后期增强，增强成分对2-APV敏感，对6-氰基-7-硝基-2，3-二酮不敏感。无镁浴液中慢信号的增强程度与2-APV诱导的慢信号减弱的程度存在地区差异。我们已经构建了与镁(2+)和2-APV敏感突触后电位相关的慢信号空间模式的早期发育图。这些图谱反映了雏鸡脑干早期发育过程中NMDA受体功能表达的空间分布。目前的发现是以前没有报道过的新数据，它们是第一次使用带有电压敏感染料的多位点光记录技术获得的。
Multiple-site optical recording of transmembrane voltage activity, using a voltage-sensitive dye (NK2761) and a 12 x 12 element photodiode array, was employed to monitor neural responses in the slice preparations that were dissected from 6–9-d-old embryonic brainstems. Transmembrane voltage-related optical responses evoked by a brief square current pulse applied with a microsuction electrode to the vagus nerve were recorded simultaneously from many sites in the preparation. In preparations from 6-d-old embryos, only action potential-related spike-like optical signals were often detected in the normal bathing solution containing 0.5 mM Mg2+. However, in several loci of some preparations, excitatory postsynaptic potential-related slow signals were elicited in a Mg(2+)-free bathing medium, and these elicited slow signals were blocked by DL-2-amino-5-phosphonovaleric acid (2-APV). These results show a possible embryonic expression of NMDA receptor- mediated excitatory postsynaptic potentials. The slow signals were usually detected from tested preparations from 7–9-d-old embryos in normal bathing solution. The later phase of the slow signals was enhanced in a Mg(2+)-free bathing medium, and the enhanced component was also sensitive to 2-APV and insensitive to 6-cyano-7- nitroquinoxaline-2,3-dione (CNQX). There were regional differences in the degree of the enhancement of the slow signals in the Mg(2+)-free bathing medium, and of the 2-APV-induced reduction of the slow signals. We have constructed early developmental maps of the spatial patterns of the slow signals related to Mg(2+)- and 2-APV-sensitive postsynaptic potentials. These maps reflect the spatial distribution of functional expression of the NMDA receptors during early development of the chick brainstem. The present findings are new data that have not been reported previously, and they have been obtained for the first time using the multiple-site optical recording technique with a voltage- sensitive dye.
孤束核中的谷氨酸机制在血压控制中。
DOI：
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发表时间：
1984
期刊：
Federation proceedings
影响因子：
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作者：
Talman,WT;Granata,AR;Reis,DJ
通讯作者：
Reis,DJ