Pitcher G M, Ritchie J, Henry J L
Department of Physiology, McGill University, 3655 Drummond Street, Montreal, Quebec, Canada.
J Neurosci Methods. 1999 Mar 1;87(2):185-93. doi: 10.1016/s0165-0270(99)00004-7.
The effect of testing surface on the rat hind paw withdrawal threshold in the von Frey hair test is investigated in this study. The data indicate that wire mesh, which is typically used to apply von Frey hairs, may have an effect on the paw withdrawal threshold. For example, in control rats tested on the wire mesh, variability in the withdrawal threshold was observed between the left and the right hind paws (51.04+/-12.29 and 64.31+/-9.37 g, respectively) and on different days of testing (35.24+/-9.54 and 45.83+/-12.97 g for the left and right hind paws, respectively, 7 days later). In an attempt to reduce this variability, a customized platform was used to measure the von Frey hair-induced paw withdrawal in the rat. It consists of an opaque, flat-surfaced plastic platform with holes through which von Frey hairs are inserted and applied to the plantar surface of the paw. In control rats tested with von Frey hairs using this customized platform, variability in the paw withdrawal thresholds between the left and right hind paws in single rats over time as well as between different rats was reduced (49.86+/-6.97 and 49.29+/-6.56 g for the left and right hind paws, respectively, on day 0; 48.29+/-5.82 and 53.00+/-4.59 g for the left and right hind paws, respectively, 7 days later). Furthermore, in rats in which a 2 mm polyethylene cuff was used to constrict the left common sciatic nerve, the ipsilateral as well as the contralateral hind paw withdrawal thresholds were decreased (2.45+/-0.65 and 26.09+/-5.86 g, respectively, 7 days later). In similar rats tested on the wire mesh, the ipsilateral but not the contralateral paw withdrawal threshold decreased (12.80+/-2.21 and 65.00+/-10.28 g, respectively, at 7 days). The data suggest that the flat surface and opaque properties of the customized platform enable accurate, reliable and repeatable measurements of ipsilateral and contralateral paw withdrawal threshold using von Frey hairs in normal and nerve-injured rats.
本研究调查了在von Frey毛发试验中测试表面对大鼠后爪缩足阈值的影响。数据表明，通常用于施加von Frey毛发的金属丝网可能会对缩足阈值产生影响。例如，在金属丝网上测试的对照大鼠中，观察到左后爪和右后爪之间（分别为51.04±12.29和64.31±9.37 g）以及在不同测试日（7天后，左后爪和右后爪分别为35.24±9.54和45.83±12.97 g）缩足阈值存在变异性。为了减少这种变异性，使用了一个定制平台来测量大鼠中von Frey毛发诱发的缩足反应。它由一个不透明的、表面平坦的塑料平台组成，该平台上有孔，von Frey毛发通过这些孔插入并施加到爪的足底表面。在使用这个定制平台用von Frey毛发测试的对照大鼠中，单只大鼠随时间以及不同大鼠之间左后爪和右后爪缩足阈值的变异性降低了（第0天，左后爪和右后爪分别为49.86±6.97和49.29±6.56 g；7天后，左后爪和右后爪分别为48.29±5.82和53.00±4.59 g）。此外，在使用2 mm聚乙烯袖带压迫左侧坐骨神经的大鼠中，同侧以及对侧后爪缩足阈值均降低（7天后分别为2.45±0.65和26.09±5.86 g）。在金属丝网上测试的类似大鼠中，同侧但不是对侧爪缩足阈值降低（7天时分别为12.80±2.21和65.00±10.28 g）。数据表明，定制平台的平坦表面和不透明特性能够在正常和神经损伤大鼠中使用von Frey毛发准确、可靠且可重复地测量同侧和对侧爪缩足阈值。
