Guertin Pierre A
Department of Anatomy and Physiology, Laval University, Neuroscience Research Center of Laval University Medical Center, Quebec City, Quebec, G1V4G2, Canada.
Neurosci Lett. 2004 Mar 25;358(2):71-4. doi: 10.1016/j.neulet.2003.12.120.
L-beta-3,4-Dihydroxyphenylalanine (L-DOPA) and quipazine, respectively dopamine/noradrenaline precursor and serotonergic (5-HT(2)) receptor agonist, were injected intraperitoneally in low-thoracic spinal mice at 7 days post-spinalization. In mice pre-treated with decarboxylase and monoamine oxydase inhibitors, L-DOPA (30-100 mg/kg) was found not to induce air-stepping. On the other hand, L-DOPA (40 mg/kg) consistently triggered locomotor-like movements if combined with low doses of quipazine (0.4-0.7 mg/kg) or if mice were placed on a motor-driven treadmill running at low speed. However, twitches, spasms, and other non-locomotor movements were also induced, especially on the treadmill. These results suggest that (1) spinal catecholaminergic and serotonergic receptors interact synergistically to generate locomotor-like movements in chronic spinal mice, and that (2) hindlimb afferent inputs associated with the treadmill conditions contribute to the genesis of locomotor-like and non-locomotor movements induced by these drugs.
L-β-3,4-二羟基苯丙氨酸（L-DOPA）和喹哌嗪，分别作为多巴胺/去甲肾上腺素前体和5-羟色胺能（5-HT(2)）受体激动剂，在脊髓损伤后7天对胸段低位脊髓小鼠进行腹腔注射。在用脱羧酶和单胺氧化酶抑制剂预处理的小鼠中，发现L-DOPA（30 - 100毫克/千克）不会诱发空中踏步。另一方面，如果与低剂量的喹哌嗪（0.4 - 0.7毫克/千克）联合使用，或者将小鼠置于低速运转的电动跑步机上，L-DOPA（40毫克/千克）会持续引发类似运动的动作。然而，也会诱发抽搐、痉挛和其他非运动性动作，尤其是在跑步机上。这些结果表明：（1）脊髓中的儿茶酚胺能和5-羟色胺能受体协同作用，在慢性脊髓小鼠中产生类似运动的动作；（2）与跑步机条件相关的后肢传入输入有助于这些药物诱发的类似运动和非运动性动作的产生。
