Optical and electrophysiological recordings of corticospinal synaptic activity and its developmental change in in vitro rat slice co-cultures
Optical and electrophysiological recordings of corticospinal synaptic activity and its developmental change in in vitro rat slice co-cultures
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DOI：
10.1016/j.neuroscience.2007.10.010
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发表时间：
2007-12-19
期刊：
影响因子：
3.3
通讯作者：
Sakurai, M.
中科院分区：
文献类型：
--
作者：
Maeda, H.;Ohno, T.;Sakurai, M.
电生理记录和光学成像与快速电压敏感染料（二-4-ANNEPS）被用来直接检查的时空特性的体外皮质脊髓突触形成的大脑皮层和脊髓切片的共培养。从脊髓细胞的全细胞记录显示单突触和多突触兴奋性突触后电流（EPSC）的刺激皮质脊髓轴突的反应。在含有高浓度二价阳离子的人工脑脊液中分离单突触EPSC和兴奋性突触后电位（EPSP）。光学成像和细胞外记录同时进行。EPSP和光学记录的兴奋性突触后电位（optEPSP）持续300-500 ms，几乎总是积极的。这些长持续电位的主要成分被艾芬地尔阻断，艾芬地尔是一种含有NR 2B亚基的N-甲基-D-天冬氨酸受体（NMDAR）的特异性拮抗剂。皮质脊髓optEPSP的空间分布与皮质脊髓场兴奋性突触后电位（fEPSP）的空间分布平行，表明正fEPSP振幅是皮质脊髓突触分布的可靠指标。皮质脊髓optEPSP在体外（DIV）6-7天扩散到腹外侧区，但在11-13 DIV时限于背内侧区，表明突触从脊髓腹外侧消除。在记录完成后，皮质脊髓纤维通常用生物胞素顺行标记，以评估突触前纤维分布与光学信号（光学记录的突触前纤维齐射（opt-prevolley）和optEPSP）之间的关系。opt-prevolleys和optEPSPs的分布与突触前纤维的分布相关性很好，表明opt-prevolleys反映了皮质脊髓纤维的活动，并且纤维沿着其轴突相对均匀地形成突触。NR 2B介导的皮质脊髓突触反应的组成部分下降之间的时间间隔6和7 DIV和11-13 DIV，这表明在NMDAR亚型从NR 2B到别的东西（可能NR 2A）的转变可能参与调节发育可塑性大鼠脊髓和皮质脊髓突触消除的过程。(c)2007年IBRO。由爱思唯尔有限公司出版。保留所有权利。
Electrophysiological recordings and optical imaging with a fast voltage-sensitive dye (di-4-ANNEPS) were used to directly examine the spatiotemporal properties of in vitro corticospinal synapses formed in co-cultures of cerebral cortex and spinal cord slices. Whole cell recordings from spinal cord cells showed both monosynaptic and polysynaptic excitatory postsynaptic currents (EPSCs) in response to stimulation of corticospinal axons. Monosynaptic EPSCs and excitatory postsynaptic potentials (EPSPs) were isolated in artificial cerebrospinal fluid containing high concentrations of divalent cations. Optical imaging and extracellular recordings were done simultaneously. Both EPSPs and optically recorded excitatory postsynaptic potentials (optEPSPs) lasted 300-500 ms and were almost always positive. The major component of these long-lasting potentials was blocked by ifenprodil, a specific antagonist of the NR2B subunit-containing N-methyl-D-aspartate receptor (NMDAR). The spatial distribution of corticospinal optEPSPs paralleled that of the corticospinal field excitatory postsynaptic potentials (fEPSPs), suggesting that positive fEPSP amplitude is a reliable indicator of the distribution of corticospinal synapses. Corticospinal optEPSPs spread into the ventrolateral region by 6-7 days in vitro (DIV), but were restricted to the dorsomedial area by 11-13 DIV, suggesting synapses were eliminated from the ventrolateral side of the spinal cord. After the recordings were complete, corticospinal fibers were often anterogradely labeled with biocytin to assess the relation between presynaptic fiber distribution and the optical signals (optically-recorded presynaptic fiber volley (opt-prevolley) and optEPSP). The distributions of the opt-prevolleys and optEPSPs correlated well with the distribution of presynaptic fibers, suggesting the opt-prevolley reflects corticospinal fiber activity and that the fibers made synapses relatively evenly along their axons. The NR2B-mediated component of the corticospinal synaptic response declined during the interval between 6 and 7 DIV and 11-13 DIV, suggesting that a shift in the NMDAR subtype from NR2B to something else (perhaps NR2A) may be involved in regulating developmental plasticity in the rat spinal cord and the process of corticospinal synapse elimination. (c) 2007 IBRO. Published by Elsevier Ltd. All rights reserved.