Name: 作者聚焦：推进脊髓刺激 - 通过膜片钳电生理学探索运动神经元的细胞反应
Uploaded: 2023-09-08T14:15:00
Description: Watch this Scientific Journal Video about Advancing Spinal Cord Stimulation - Exploring the Cellular Responses of Motor Neurons Through Patch-Clamp Electrophysiology at JoVE.com

本研究由国家自然科学基金青年基金（52207254和82301657）和中国博士后科学基金（2022M711833）资助。

机构动物护理和使用委员会批准了所有动物实验，研究是按照相关的动物福利法规进行的。
1. 动物准备
<ol><li>动物<ol><li>饲养信息：在特定的无病原体环境中饲养雄性Sprague-Dawley大鼠（出生后10-14天，P10-P14）。 注意：室温保持在20°C±2°C，湿度：50%-60%，光/暗循环12小时。动物可以自由获得食物和水。</li>
		<li>逆行标记运动神经元：将氟金（FG）注射到双侧胫骨...

了解运动神经元对脊髓刺激的反应

<ol>
	<li>Rowald, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Activity-dependent+spinal+cord+neuromodulation+rapidly+restores+trunk+and+leg+motor+functions+after+complete+paralysis.">Activity-dependent spinal cord neuromodulation rapidly restores trunk and leg motor functions after complete paralysis.</a> Nature Medicine. 28 (2), 260-271 (2022).</li><li>Kathe, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+neurons+that+restore+walking+after+paralysis.">The neurons that restore walking after paralysis.</a> Nature. 611 (7936), 540-547 (2022).</li><li>Smith, S. J., Buchanan, J., Osses, L. R., Charlton, M. P., Augustine, G. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+spatial+distribution+of+calcium+signals+in+squid+presynaptic+terminals.">The spatial distribution of calcium signals in squid presynaptic terminals.</a> The Journal of Physiology. 472, 573-593 (1993).</li><li>Augustine, G. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Regulation+of+transmitter+release+at+the+squid+giant+synapse+by+presynaptic+delayed+rectifier+potassium+current.">Regulation of transmitter release at the squid giant synapse by presynaptic delayed rectifier potassium current.</a> The Journal of Physiology. 431, 343-364 (1990).</li><li>Llin&#225;s, R., McGuinness, T. L., Leonard, C. S., Sugimori, M., Greengard, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intraterminal+injection+of+synapsin+I+or+calcium/calmodulin-dependent+protein+kinase+II+alters+neurotransmitter+release+at+the+squid+giant+synapse.">Intraterminal injection of synapsin I or calcium/calmodulin-dependent protein kinase II alters neurotransmitter release at the squid giant synapse.</a> Proceedings of the National Academy of Sciences of the United States of America. 82 (9), 3035-3039 (1985).</li><li>Formento, E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrical+spinal+cord+stimulation+must+preserve+proprioception+to+enable+locomotion+in+humans+with+spinal+cord+injury.">Electrical spinal cord stimulation must preserve proprioception to enable locomotion in humans with spinal cord injury.</a> Nature Neuroscience. 21 (12), 1728-1741 (2018).</li><li>Hari, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=GABA+facilitates+spike+propagation+through+branch+points+of+sensory+axons+in+the+spinal+cord.">GABA facilitates spike propagation through branch points of sensory axons in the spinal cord.</a> Nature Neuroscience. 25 (10), 1288-1299 (2022).</li><li>Sakmann, B., Neher, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Patch+clamp+techniques+for+studying+ionic+channels+in+excitable+membranes.">Patch clamp techniques for studying ionic channels in excitable membranes.</a> Annual Review Of Physiology. 46, 455-472 (1984).</li><li>Leroy, F., Lamotte d'Incamps, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+preparation+of+oblique+spinal+cord+slices+for+ventral+root+stimulation.">The preparation of oblique spinal cord slices for ventral root stimulation.</a> Journal of Visualized Experiments:JoVE. (116), e54525 (2016).</li><li>Sharples, S. A., Miles, G. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Maturation+of+persistent+and+hyperpolarization-activated+inward+currents+shapes+the+differential+activation+of+motoneuron+subtypes+during+postnatal+development.">Maturation of persistent and hyperpolarization-activated inward currents shapes the differential activation of motoneuron subtypes during postnatal development.</a> Elife. 10, e71385 (2021).</li><li>Bhumbra, G. S., Beato, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recurrent+excitation+between+motoneurones+propagates+across+segments+and+is+purely+glutamatergic.">Recurrent excitation between motoneurones propagates across segments and is purely glutamatergic.</a> PLoS Biology. 16 (3), e2003586 (2018).</li><li>Leroy, F., Lamotte d'Incamps, B., Imhoff-Manuel, R. D., Zytnicki, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Early+intrinsic+hyperexcitability+does+not+contribute+to+motoneuron+degeneration+in+amyotrophic+lateral+sclerosis.">Early intrinsic hyperexcitability does not contribute to motoneuron degeneration in amyotrophic lateral sclerosis.</a> Elife. 3, 04046 (2014).</li><li>Tahir, R. A., Pabaney, A. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Therapeutic+hypothermia+and+ischemic+stroke:+A+literature+review.">Therapeutic hypothermia and ischemic stroke: A literature review.</a> Surgical Neurology International. 7, S381-S386 (2016).</li><li>Lu, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Management+of+intractable+pain+in+patients+with+implanted+spinal+cord+stimulation+devices+during+the+COVID-19+pandemic+using+a+remote+and+wireless+programming+system.">Management of intractable pain in patients with implanted spinal cord stimulation devices during the COVID-19 pandemic using a remote and wireless programming system.</a> Frontiers in Neuroscience. 14, 594696 (2020).</li><li>Yao, Q., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Wireless+epidural+electrical+stimulation+in+combination+with+serotonin+agonists+improves+intraspinal+metabolism+in+spinal+cord+injury+rats.">Wireless epidural electrical stimulation in combination with serotonin agonists improves intraspinal metabolism in spinal cord injury rats.</a> Neuromodulation. 24 (3), 416-426 (2021).</li><li>Arlotti, M., Rahman, A., Minhas, P., Bikson, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Axon+terminal+polarization+induced+by+weak+uniform+dc+electric+fields:+a+modeling+study.">Axon terminal polarization induced by weak uniform dc electric fields: a modeling study.</a> 2012 Annual International Conference of the IEEE Engineering in Medicine and Biology Society. , 4575-4578 (2012).</li><li>Espino, C. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Na(V)1.1+is+essential+for+proprioceptive+signaling+and+motor+behaviors.">Na(V)1.1 is essential for proprioceptive signaling and motor behaviors.</a> Elife. 11, e79917 (2022).</li><li>Romer, S. H., Deardorff, A. S., Fyffe, R. E. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+molecular+rheostat:+Kv2.1+currents+maintain+or+suppress+repetitive+firing+in+motoneurons.">A molecular rheostat: Kv2.1 currents maintain or suppress repetitive firing in motoneurons.</a> The Journal of Physiology. 597 (14), 3769-3786 (2019).</li><li>Yao, X., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Structures+of+the+R-type+human+Ca(v)2.3+channel+reveal+conformational+crosstalk+of+the+intracellular+segments.">Structures of the R-type human Ca(v)2.3 channel reveal conformational crosstalk of the intracellular segments.</a> Nature Communications. 13 (1), 7358 (2022).</li><li>Bandres, M. F., Gomes, J., McPherson, J. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spontaneous+multimodal+neural+transmission+suggests+that+adult+spinal+networks+maintain+an+intrinsic+state+of+readiness+to+execute+sensorimotor+behaviors.">Spontaneous multimodal neural transmission suggests that adult spinal networks maintain an intrinsic state of readiness to execute sensorimotor behaviors.</a> Journal Of Neuroscience. 41 (38), 7978-7990 (2021).</li><li>Manuel, M., Heckman, C. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Simultaneous+intracellular+recording+of+a+lumbar+motoneuron+and+the+force+produced+by+its+motor+unit+in+the+adult+mouse+in+vivo.">Simultaneous intracellular recording of a lumbar motoneuron and the force produced by its motor unit in the adult mouse in vivo.</a> Journal of Visualized Experiments: JoVE. (70), e4312 (2012).</li><li>Luo, X., Wang, S., Rutkove, S. B., Sanchez, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nonhomogeneous+volume+conduction+effects+affecting+needle+electromyography:+an+analytical+and+simulation+study.">Nonhomogeneous volume conduction effects affecting needle electromyography: an analytical and simulation study.</a> Physiological Measurement. 42 (11), (2021).</li><li>Barra, B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Epidural+electrical+stimulation+of+the+cervical+dorsal+roots+restores+voluntary+upper+limb+control+in+paralyzed+monkeys.">Epidural electrical stimulation of the cervical dorsal roots restores voluntary upper limb control in paralyzed monkeys.</a> Nature Neuroscience. 25 (7), 924-934 (2022).</li><li>Powell, M. P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Epidural+stimulation+of+the+cervical+spinal+cord+for+post-stroke+upper-limb+paresis.">Epidural stimulation of the cervical spinal cord for post-stroke upper-limb paresis.</a> Nature Medicine. 29 (3), 689-699 (2023).</li><li>Wenger, N., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spatiotemporal+neuromodulation+therapies+engaging+muscle+synergies+improve+motor+control+after+spinal+cord+injury.">Spatiotemporal neuromodulation therapies engaging muscle synergies improve motor control after spinal cord injury.</a> Nature Medicine. 22 (2), 138-145 (2016).</li><li>&#214;zyurt, M. G., Ojeda-Alonso, J., Beato, M., Nascimento, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vitro+longitudinal+lumbar+spinal+cord+preparations+to+study+sensory+and+recurrent+motor+microcircuits+of+juvenile+mice.">In vitro longitudinal lumbar spinal cord preparations to study sensory and recurrent motor microcircuits of juvenile mice.</a> Journal of Neurophysiology. 128 (3), 711-726 (2022).</li><li>Moraud, E. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanisms+underlying+the+neuromodulation+of+spinal+circuits+for+correcting+gait+and+balance+deficits+after+spinal+cord+injury.">Mechanisms underlying the neuromodulation of spinal circuits for correcting gait and balance deficits after spinal cord injury.</a> Neuron. 89 (4), 814-828 (2016).</li><li>Capogrosso, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+computational+model+for+epidural+electrical+stimulation+of+spinal+sensorimotor+circuits.">A computational model for epidural electrical stimulation of spinal sensorimotor circuits.</a> Journal of Neuroscience. 33 (49), 19326-19340 (2013).</li></ol>

SCS调制的运动信息最终收敛到运动神经元。因此，以运动神经元为研究靶点可以简化研究设计，更直接地揭示SCS的神经调控机制。为了同时记录不同的刺激特征和细胞反应，膜片钳是在单细胞尺度上研究电生理特征的好方法。然而，仍然存在一些困难，包括如何保持细胞活力，如何快速将脊髓与骨结构分离，以及如何利用SCS成功诱导APs。因此，本研究旨在帮助研究人员快速掌握基本的操作技能，?...

脊髓刺激（SCS）可有效恢复脊髓损伤（SCI）后的运动功能。Andreas Rowald 等人报告说，SCS 在一天内实现了下肢运动和躯干功能1.探索SCS对运动恢复的生物学机制是制定更精确的SCS策略的关键和趋势研究领域。例如，Grégoire Courtine的团队证明，脊髓中的兴奋性Vsx2中间神经元和Hoxa10神经元是响应SCS的关键神经元，细胞特异性神经调控在SCI2后恢复大鼠行走能力是可行的。然而，很少有研究关注单细胞尺度上SCS的电机制。尽管众所周知，超阈值直流电刺激可以引发经典鱿鱼实验3,4,5中的动作电位（AP），但脉冲交变电刺激（如SCS）如何影响运动信号的产生仍不清楚。
鉴于脊髓内神经回路的复杂性，适当选择细胞群对于研究SCS的电机制非常重要。尽管 SCS 通过激活本体感受通路6 来恢复运动功能，但运动神经元是执行运动命令的最终单元，该命令来自整合本体感受信息传入输入7。因此，直接用SCS研究运动神经元的电特性可以帮助我们理解脊髓运动调节的底层逻辑。
众所周知，膜片钳是细胞电生理记录的金标准方法，具有极高的时空分辨率8。因此，本研究描述了一种使用膜片钳研究运动神经元对SCS的电反应的方法。与脑膜片钳9相比，脊髓膜片钳的难度更大，原因如下：（1）脊髓由体积小的椎管保护，需要非常精细的显微操作和严格的冰冷维护才能获得更好的细胞活力。（2）由于脊髓太细，无法固定在切割盘上，应将其浸入低熔点琼脂糖中，固化后进行修整。
因此，该方法在解剖脊髓和保持细胞活力的同时提供了技术细节，从而顺利地研究SCS对运动神经元的电机制，避免不必要的试验和错误。

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Adenosine 5&#8217;-triphosphate magnesium salt</td>
			<td>Sigma</td>
			<td>A9187</td>
			<td></td>
		</tr>
		<tr>
			<td>Ascorbic Acid</td>
			<td>Sigma</td>
			<td>A4034</td>
			<td></td>
		</tr>
		<tr>
			<td>CaCl2&#183;2H2O</td>
			<td>Sigma</td>
			<td>C5080</td>
			<td></td>
		</tr>
		<tr>
			<td>Choline Chloride</td>
			<td>Sigma</td>
			<td>C7527</td>
			<td></td>
		</tr>
		<tr>
			<td>Cover slide tweezers</td>
			<td>VETUS</td>
			<td>36A-SA</td>
			<td>Clip a slice</td>
		</tr>
		<tr>
			<td>D-Glucose</td>
			<td>Sigma</td>
			<td>G8270</td>
			<td></td>
		</tr>
		<tr>
			<td>EGTA</td>
			<td>Sigma</td>
			<td>E4378</td>
			<td></td>
		</tr>
		<tr>
			<td>Fine scissors</td>
			<td>RWD Life Science</td>
			<td>S12006-10</td>
			<td>Cut the diaphragm</td>
		</tr>
		<tr>
			<td>Fluorescence Light Source</td>
			<td>Olympus&#160;</td>
			<td>U-HGLGPS</td>
			<td></td>
		</tr>
		<tr>
			<td>Fluoro-Gold</td>
			<td>Fluorochrome</td>
			<td>Fluorochrome</td>
			<td>Label the motor neuron</td>
		</tr>
		<tr>
			<td>Guanosine 5&#8242;-triphosphate sodium salt hydrate</td>
			<td>Sigma</td>
			<td>G8877</td>
			<td></td>
		</tr>
		<tr>
			<td>HEPES</td>
			<td>Sigma</td>
			<td>H3375</td>
			<td></td>
		</tr>
		<tr>
			<td>infrared CCD camera</td>
			<td>Dage-MTI</td>
			<td>IR-1000E</td>
			<td></td>
		</tr>
		<tr>
			<td>KCl</td>
			<td>Sigma</td>
			<td>P5405</td>
			<td></td>
		</tr>
		<tr>
			<td>K-gluconate</td>
			<td>Sigma</td>
			<td>P1847</td>
			<td></td>
		</tr>
		<tr>
			<td>Low melting point agarose</td>
			<td>Sigma</td>
			<td>A9414</td>
			<td></td>
		</tr>
		<tr>
			<td>MgSO4&#183;7H2O</td>
			<td>Sigma</td>
			<td>M2773</td>
			<td></td>
		</tr>
		<tr>
			<td>Micromanipulator&#160;</td>
			<td>Sutter Instrument&#160;</td>
			<td>MP-200</td>
			<td></td>
		</tr>
		<tr>
			<td>Micropipette puller</td>
			<td>Sutter instrument</td>
			<td>P1000</td>
			<td></td>
		</tr>
		<tr>
			<td>Micro-scissors&#160;</td>
			<td>Jinzhong</td>
			<td>wa1020</td>
			<td>Laminectomy</td>
		</tr>
		<tr>
			<td>Microscope for anatomy</td>
			<td>Olympus&#160;</td>
			<td>SZX10</td>
			<td></td>
		</tr>
		<tr>
			<td>Microscope for ecletrophysiology</td>
			<td>Olympus&#160;</td>
			<td>BX51WI</td>
			<td></td>
		</tr>
		<tr>
			<td>Micro-toothed tweezers</td>
			<td>RWD Life Science</td>
			<td>F11008-09</td>
			<td>Lift the cut vertebral body</td>
		</tr>
		<tr>
			<td>NaCl</td>
			<td>Sigma</td>
			<td>S5886</td>
			<td></td>
		</tr>
		<tr>
			<td>NaH2PO4</td>
			<td>Sigma</td>
			<td>S8282</td>
			<td></td>
		</tr>
		<tr>
			<td>NaHCO3</td>
			<td>Sigma</td>
			<td>V900182</td>
			<td></td>
		</tr>
		<tr>
			<td>Na-Phosphocreatine</td>
			<td>Sigma</td>
			<td>P7936</td>
			<td></td>
		</tr>
		<tr>
			<td>Objective lens for ecletrophysiology</td>
			<td>Olympus&#160;</td>
			<td>LUMPLFLN60XW</td>
			<td>working distance 2 mm&#160;</td>
		</tr>
		<tr>
			<td>Osmometer&#160;</td>
			<td>Advanced&#160;</td>
			<td>FISKE 210</td>
			<td></td>
		</tr>
		<tr>
			<td>Patch-clamp amplifier&#160;</td>
			<td>Axon&#160;</td>
			<td>Multiclamp 700B</td>
			<td></td>
		</tr>
		<tr>
			<td>Patch-clamp digitizer</td>
			<td>Axon&#160;</td>
			<td>Digidata 1550B</td>
			<td></td>
		</tr>
		<tr>
			<td>pH meter&#160;</td>
			<td>Mettler Toledo&#160;</td>
			<td>FE28</td>
			<td></td>
		</tr>
		<tr>
			<td>Slice Anchor</td>
			<td>Multichannel system</td>
			<td>SHD-27H</td>
			<td></td>
		</tr>
		<tr>
			<td>Spinal cord stimulatior</td>
			<td>PINS</td>
			<td>T901</td>
			<td></td>
		</tr>
		<tr>
			<td>Toothed tweezer</td>
			<td>RWD Life Science</td>
			<td>F13030-10</td>
			<td>Lift the xiphoid</td>
		</tr>
		<tr>
			<td>Vibratome</td>
			<td>Leica</td>
			<td>VT1200S</td>
			<td></td>
		</tr>
		<tr>
			<td>Wide band ultraviolet excitation filter</td>
			<td>Olympus&#160;</td>
			<td>U-MF2</td>
			<td></td>
		</tr>
	</tbody>
</table>

the ex vivo preparation of spinal cord slice for the whole-cell patch-clamp recording in motor neurons during spinal cord stimulation

脊髓刺激（SCS）可有效恢复脊髓损伤（SCI）后的运动功能。由于运动神经元是执行感觉运动行为的最终单位，因此直接研究SCS运动神经元的电反应可以帮助我们理解脊髓运动调节的底层逻辑。为了同时记录不同的刺激特征和细胞反应，膜片钳是在单细胞尺度上研究电生理特征的好方法。然而，实现这一目标仍然存在一些复杂的困难，包括维持细胞活力、快速将脊髓与骨结构分离，以及利用SCS成功诱导动作电位。在这里，我们提出了一个详细的方案，使用膜片钳以高时空分辨率研究运动神经元对SCS的电反应，这可以帮助研究人员提高分离脊髓和维持细胞活力的技能，以顺利研究SCS对运动神经元的电机制，避免不必要的试验和错误。

Spinal cord stimulation (SCS) can effectively restore locomotor function after spinal cord injury (SCI). Andreas Rowald et al. reported that SCS enables lower limb locomotor and trunk function within a single day1. Exploring the biological mechanism of SCS for locomotor recovery is a critical and trending research field for developing a more precise SCS strategy. For example, Gr&#233;goire Courtine&#39;s team demonstrated that excitatory Vsx2 interneuron and Hoxa10 neurons in the spinal cord are the key neurons to response to SCS, and cell-specific neuromodulation is feasible to restore the rat walking ability after SCI2. However, few studies focus on the electrical mechanism of SCS at a single-cell scale. Although it is well-known that the suprathreshold direct current stimulus can elicit the action potentials (APs) in the classic squid experiment3,4,5, how the pulsed alternating electrical stimulation, such as SCS, affects the motor signal generation is still unclear.
Given the complexity of intraspinal neural circuits, appropriate selection for cell population is important for investigating the electrical mechanism of SCS. Although SCS restores motor function by activating the proprioceptive pathway6, the motor neurons are the final unit to execute the motor command, derived from integrating proprioception information afferent input7. Therefore, directly studying the electrical characteristics of motor neurons with SCS can help us understand the underlying logic of spinal motor modulation.
As we know, patch-clamp is the golden-standard method for cellularly electrophysiological recording with extremely high spatiotemporal resolution8. Therefore, this study describes a method using a patch clamp to study the electrical responses of motor neurons to SCS. Compared with the brain patch-clamp9, the spinal cord patch-clamp is more difficult due to the following reasons: (1) The spinal cord is protected by the vertebral canal with tiny volume, which requires very fine micromanipulation and rigorous ice-cold maintenance to obtain better cell viability. (2) Because the spinal cord is too slender to be secured on the cutting tray, it should be immersed in low-melting point agarose and trimmed after solidification.
Hence, this method provides technical details in dissecting the spinal cord and maintaining the cell viability at the same time so as to smoothly study the electrical mechanism of SCS on motor neurons and avoid unnecessary trials and mistakes.

作者聚焦：推进脊髓刺激 - 通过膜片钳电生理学探索运动神经元的细胞反应 

脊髓切片 的离体 制备，用于脊髓刺激过程中运动神经元的全细胞膜片钳记录

Spinal cord stimulation can help patients resolve most motion functions after injury. Most neurons are to execute sensory mode behaviors. Studying the electric response of most neurons can aid in understanding the underlying logic of spinal load neuromodulation.A patch clamp is the golden standard method for cellular electrophysiological recordings with the extremely high spatial temporal resolution. Therefore, this study describes a method using a patch clamp to simultaneously record the aortas stimulus characteristics and cellular responses of motor neurons at a single-cell scale. Compared with the brain patch clamp, the spinal cord patch clamp is more difficult, because the spinal cord is well protected by the vertebral canal with tiny volume.Therefore, this protocol provides technical details in quickly micro dissecting the spinal cord and reverse maintenance to obtain better cell viability. Patch clamp allows a unique understanding of the synaptic transmissions and the understanding of action potentials, coding pattern activities by the spinal cord stimulation.

由于精细操作期间严格的低温维护（补充图1、补充图2和图1），细胞活力足以进行后续的电生理记录。为了尽可能地模拟临床场景，我们使用显微操作将 SCS 阴极和阳极分别放置在背中线和 DREZ 附近（图 2），这可以启动背角中的神经信号传播到运动柱背外侧区域的运动神经元。在这项研究中，我们使用FG定位直径为20-50μm的运动神经元。<st...

Watch this Scientific Journal Video about Advancing Spinal Cord Stimulation - Exploring the Cellular Responses of Motor Neurons Through Patch-Clamp Electrophysiology at JoVE.com

该协议描述了一种使用膜片钳研究运动神经元对脊髓刺激（SCS）的电反应的方法，具有高时空分辨率，这可以帮助研究人员提高分离脊髓和同时维持细胞活力的技能。

Spinal cord stimulation (SCS) can effectively restore locomotor function after spinal cord injury (SCI). Because the motor neurons are the final unit to ...

脊髓刺激可以帮助患者在受伤后解决大多数运动功能。大多数神经元执行感觉模式行为。研究大多数神经元的电反应可以帮助理解脊髓负荷神经调控的潜在逻辑。膜片钳是细胞电生理记录的黄金标准方法，具有极高的空间时间分辨率。因此，本研究描述了一种使用膜片钳在单细胞尺度上同时记录运动神经元的主动脉刺激特征和细胞反应的方法。与脑膜片钳相比，脊髓膜片钳的难度更大，因为脊髓被体积小的椎管很好地保护了。因此，该协议提供了快速显微解剖脊髓和反向维持以获得更好的细胞活力的技术细节。膜片钳可以对突触传递和动作电位的理解有独特的理解，通过脊髓刺激编码模式活动。

the-ex-vivo-preparation-spinal-cord-slice-for-whole-cell-patch-clamp

Research

JoVE Journal

Neuroscience

The Ex vivo Preparation of Spinal Cord Slice for the Whole-Cell Patch-Clamp Recording in Motor Neurons During Spinal Cord Stimulation

Spinal cord stimulation (SCS) can effectively restore locomotor function after spinal cord injury (SCI). Because the motor neurons are the final unit to execute sensorimotor behaviors, directly studying the electrical responses of motor neurons with SCS can help us understand the underlying logic of spinal motor modulation. To simultaneously record diverse stimulus characteristics and cellular responses, a patch-clamp is a good method to study the electrophysiological characteristics at a single-cell scale. However, there are still some complex difficulties in achieving this goal, including maintaining cell viability, quickly separating the spinal cord from the bony structure, and using the SCS to successfully induce action potentials. Here, we present a detailed protocol using patch-clamp to study the electrical responses of motor neurons to SCS with high spatiotemporal resolution, which can help researcher improve their skills in separating the spinal cord and maintaining the cell viability at the same time to smoothly study the electrical mechanism of SCS on motor neuron and avoid unnecessary trial and mistake.

This protocol describes a method using a patch-clamp to study the electrical responses of motor neurons to spinal cord stimulation (SCS) with high spatiotemporal resolution, which can help researchers improve their skills in separating the spinal cord and maintaining cell viability simultaneously.

科研

神经科学

Spinal Cord Dissection for the Whole-Cell Patch-Clamp Recording in Motor Neurons

After exposing the heart of an anesthetized rat, cut the right atrium using fine scissors and inject 100 milliliters of chilled perfusing fluid at approximately two milliliters per second within one minute. Position the rat in the prone position. Cut the spine at the anterior superior iliac spine and the curvature shifting point of the thoracic column.Immediately place the isolated spine into the oxygenated ice cold perfusing solution to wash off residual blood and fat tissue. Then transfer the isolated spine to the anatomical tray with its dorsal side up and the rostral end near the operator. Fill the tray with 50 milliliters of continuously oxygenated ice cold cutting solution.Under a dissection microscope, cut the vertebral pedicles on both sides from the rostral end using micro scissors. Next, delicately sever the dura mater along its dorsal midline with micro scissors. Lift the rostral part of the spinal cord carefully and cut the nerve root, leaving about one millimeter reserved.After the spinal cord has been separated from the vertebral canal, secure it with the ventral side facing up using two insect pins. Trim any excessive nerve roots, leaving about one millimeter intact. Then separate the lumbar enlargement to a length of six to seven millimeters using a micro scissor.

脊髓解剖用于运动神经元中全细胞膜片钳记录

Preparation of Spinal Cord Slice for the Whole-Cell Patch-Clamp Recording in Motor Neurons

After dissecting the spinal cord and separating the lumbar enlargement, place the lumbar enlargement on a 35 degree slope with the dorsal side up and the caudal side down. Absorb any excess water on the tissue surface using an absorbent filter paper. Carefully pour the molten agarose gel into the Petri dish containing the lumbar enlargement.Position the Petri dish in the ice water mixture to ensure rapid gel cooling. Shape the gel into a cube of 15 by 10 by 10 millimeters, and mount it onto the specimen disc using super glue. Adjust the vibratome settings to a thickness of 350 micrometers, a speed of 0.14 to 0.16 millimeters per second, an amplitude of one millimeter, and a vibration frequency of 85 hertz.Now, use the cover slide tweezers to clip a slice and place it into the incubation chamber, filled with continuously oxygenated artificial cerebrospinal fluid.

用于运动神经元全细胞膜片钳记录的脊髓切片的制备

Patch-Clamp Recording to Study the Electrical Responses of Motor Neurons to Spinal Cord Stimulation

To begin, place the prepared spinal cord slice in the recording chamber. Then place the anode of the micro-manipulation system near the dorsal midline in the cathode close to the dorsal root entry zone for proper spinal cord stimulator positioning. Now switch to a 60X objective lens to identify a healthy neuron having a smooth and bright surface without visible nuclei.Slightly decrease the infrared intensity, turn on the fluorescent light source, and adjust the light filter to the wideband ultraviolet excitation option. Now, select an appropriate Fluoro-Gold-positive motor neuron and gradually lower the electrode until it is near the neuron. As the pipette contacts its surface, look for a small membrane indentation at the tip level and release the previously-applied positive pressure.Then apply negative pressure to the pipette using a syringe and wait until the resistance value rises to gigaohms on the software interface. Clamp the membrane potential at minus 70 millivolts. Press the fast capacitance compensation button on the amplifier's software interface, then apply a brief negative pressure to rupture the cell membrane and press the slow capacitance compensation button on the amplifier's software interface.Apply the spinal cord stimulation for one to two seconds keeping the amplitude between one and 10 milliamperes. Determine the motor threshold by gradually increasing the stimulation amplitude until the first action potential is observed. Distinguish delayed and immediate firing motor neurons using a five-second depolarizing current injection around rheobase in the current clamp mode.After turning off the spinal cord stimulation, continue recording the membrane potentials to capture the spontaneous action potentials firing. When the amplitude of spinal cord stimulation was raised, the membrane potential was increased, and the action potentials were triggered every 10 to 20 pulses. After the spinal cord stimulation was turned off, the neuron fired a series of spontaneous action potentials for a short period of time.Then, the resting membrane potential returned to minus 65 millivolts.