Sonnhof U, Förderer R, Schneider W, Kettenmann H
Pflugers Arch. 1982 Jan;392(3):295-300. doi: 10.1007/BF00584314.
A small angle stepping motor was used for construction of a micropositioner. Linear movements are produced by direct coupling of the rotor axis to high precision microdrive. The linearly moving system is constructed from stainless steal prismatic guides with hardened surfaces and permits precise steps in the 100 nm range. Extreme reduction of the moving masses and minimal friction of the radial thrust bearing enables strong acceleration of the electrode. During simultaneous measurements of step performance motoneurons in the frog spinal cord, CA 1 cells of hippocampal brain slices and glia cells in tissue culture were punctured with single electrodes (tip less than l micron and double barrelled ion-sensitive microelectrodes (phi 1,5-2 micron). In all three preparations, cell penetration could be performed by means of both types of electrodes with a high yield when the step velocity reached or exceeded 4 mm/s. Steps with lower velocity resulted in less successful cell penetrations and were accompanied by typical dimpling effects. The results indicate that a critical velocity is required for cell puncturing with a minimum of damage.
使用一个小角度步进电机构建了一个微定位器。通过将转子轴直接连接到高精度微驱动器来产生线性运动。线性移动系统由具有硬化表面的不锈钢棱柱形导轨构成，可实现100纳米范围内的精确步长。移动质量的极大降低以及径向推力轴承的最小摩擦使得电极能够实现强力加速。在对青蛙脊髓中的运动神经元、海马脑片的CA1细胞以及组织培养中的神经胶质细胞进行步长性能同步测量期间，用单电极（尖端小于1微米）和双管离子敏感微电极（直径1.5 - 2微米）对其进行穿刺。在所有这三种制备物中，当步长速度达到或超过4毫米/秒时，两种类型的电极都能以高产率进行细胞穿刺。速度较低的步长导致细胞穿刺成功率较低，并伴有典型的压痕效应。结果表明，细胞穿刺需要一个临界速度以将损伤降至最低。
