Hohmann A G, Tsou K, Walker J M
Department of Psychology, Brown University, Providence, RI 02912, USA.
Neurosci Lett. 1998 Dec 4;257(3):119-22. doi: 10.1016/s0304-3940(98)00802-7.
The effects of spinally administered cannabinoids on nociceptive responses of wide dynamic range (WDR) neurons in the lumbar spinal cord were investigated in urethane-anesthetized rats. Noxious thermal stimulation was applied with a Peltier device to regions of the ipsilateral hindpaw corresponding to the receptive fields of isolated neurons. WIN55,212-2 (100 microg, i.t.), applied topically on the dorsal spinal surface, suppressed noxious heat-evoked activity in spinal WDR neurons. By contrast, responsiveness was unchanged following administration of either vehicle or WIN55,212-3, the receptor-inactive enantiomer. WIN55,212-2, administered intrathecally to separate rats, produced antinociceptive effects in the tail-flick test with a time course and efficacy that paralleled the suppression of noxious heat-evoked activity. These results suggest that cannabinoid modulation of spinal nociceptive processing involves direct actions in the spinal dorsal horn and is related to the antinociceptive effects of intrathecally administered cannabinoids.
在乌拉坦麻醉的大鼠中，研究了脊髓给予大麻素对腰段脊髓广动力范围（WDR）神经元伤害性反应的影响。用珀耳帖装置对与分离神经元感受野相对应的同侧后爪区域施加有害热刺激。将WIN55,212-2（100微克，鞘内注射）局部应用于脊髓背表面，可抑制脊髓WDR神经元中有害热诱发的活动。相比之下，给予载体或受体无活性对映体WIN55,212-3后，反应性没有变化。将WIN55,212-2鞘内注射给另外的大鼠，在甩尾试验中产生了镇痛作用，其时程和效力与有害热诱发活动的抑制情况平行。这些结果表明，大麻素对脊髓伤害性处理的调节涉及脊髓背角的直接作用，并且与鞘内给予大麻素的镇痛作用有关。
