In vivo microelectrode track reconstruction using magnetic resonance imaging
In vivo microelectrode track reconstruction using magnetic resonance imaging
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DOI：
10.1016/s0165-0270(98)00003-x
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发表时间：
1998-04-30
影响因子：
3
通讯作者：
Born, RT
中科院分区：
文献类型：
--
作者：
Fung, SH;Burstein, D;Born, RT
为了获得更精确的关于微电极记录和微刺激实验中警觉动物皮质部位的解剖学信息，我们开发了一种非侵入性的磁共振成像（MRI）技术来重建微电极轨迹。我们在被麻醉的大鼠的大脑中制造了微电极，并通过不锈钢微电极尖端的阳极单相或双相电流沉积金属（可能是铁）来标记它们的位置。在4.7T MRI扫描仪上使用梯度回波序列，金属沉积物在活体动物中清晰可见，为约200 μ m宽的低信号点状标记。我们通过将其直接与死后组织学进行比较来证实MRI的发现，其中沉积物中的铁可以通过普鲁士蓝反应可见。低至1 μ A（阳极）的电流持续5秒就能产生核磁共振可见标记，这些标记在活体大鼠的大脑中保持稳定长达9个月。我们可以用直流电或双相电流脉冲来做标记。双相脉冲造成的组织损伤较小，与许多实验室在警觉的猴子大脑中进行的功能性微刺激研究类似。(C) 1998 Elsevier Science B.V.版权所有
To obtain more precise anatomical information about cortical sites of microelectrode recording and microstimulation experiments in alert animals, we have developed a non-invasive, magnetic resonance imaging (MRI) technique for reconstructing microelectrode tracks. We made microelectrode penetrations in the brains of anesthetized rats and marked sites along them by depositing metal, presumably iron, with anodic monophasic or biphasic current from the tip of a stainless steel microelectrode. The metal deposits were clearly visible in the living animal as approximately 200 mu m wide hypointense punctate marks using gradient echo sequences in a 4.7T MRI scanner. We confirmed the MRI findings by comparing them directly to the postmortem histology in which the iron in the deposits could be rendered visible with a Prussian blue reaction. MRI-visible marks could be created using currents as low as 1 mu A (anodic) for 5 s, and they remained stable in the brains of living rats for up to nine months. We were able to make marks using either direct current or biphasic current pulses. Biphasic pulses caused less tissue damage and were similar to those used by many laboratories for functional microstimulation studies in the brains of alert monkeys. (C) 1998 Elsevier Science B.V. All rights reserved.