Gaudin D P, St-Pierre J A, Lavoie B, Bédard P J
Department of Pharmacology, Laval University, Québec, Canada.
Exp Neurol. 1994 May;127(1):45-53. doi: 10.1006/exnr.1994.1078.
In the present study, we have investigated the effect of a unilateral 6-hydroxydopamine lesion of the nigrostriatal pathway and of a fetal nigral graft in the striatum on circling induced by unilateral microinjection of muscimol in a target structure of the striatum, the substantia nigra pars reticulata. A group of ovariectomized female rats received a unilateral nigral lesion with 6-hydroxydopamine. The lesioned animals were then tested for apomorphine circling (0.25 mg/kg sc). The animals which displayed circling with this drug were divided into two groups with equivalent circling rate. One group received a graft of 1.5 x 10(6) cells taken from the ventral mesencephalon of 14- to 15-day-old rat embryos and the other was kept as control. Six months after the graft, all animals received one microinjection on each side of the GABAergic agonist muscimol (25 ng/0.5 microliters) in site A (rostral part) or in site B (caudal part) of the substantia nigra pars reticulata using indwelling guide cannulae. Circling was monitored during 90 min after the injection. Our results show that: (1) Unilateral degeneration of the nigrostriatal pathway was associated with a decrease of contralateral rotation when muscimol was injected in site A (rostral part) and an increase when administrated in site B (caudal part) of the substantia nigra pars reticulata on the lesioned side compared to the intact side. (2) A fetal nigral graft implanted into the striatum can normalize the changes in GABAergic sensitivity in site A but not in site B of the substantia nigra pars reticulata.
在本研究中，我们研究了黑质纹状体通路单侧6-羟基多巴胺损伤以及纹状体内胎儿黑质移植对在纹状体的一个靶结构黑质网状部中单侧微量注射蝇蕈醇所诱导的转圈行为的影响。一组去卵巢的雌性大鼠接受了单侧黑质6-羟基多巴胺损伤。然后对损伤动物进行阿扑吗啡诱导的转圈行为测试（皮下注射0.25mg/kg）。表现出对该药有转圈行为的动物被分为两组，转圈率相当。一组接受了取自14至15日龄大鼠胚胎腹侧中脑的1.5×10(6)个细胞的移植，另一组作为对照。移植后6个月，所有动物使用留置引导套管在黑质网状部的A区（前部）或B区（后部）两侧各微量注射一次GABA能激动剂蝇蕈醇（25ng/0.5微升）。注射后90分钟内监测转圈行为。我们的结果表明：（1）当在损伤侧黑质网状部的A区（前部）注射蝇蕈醇时，黑质纹状体通路的单侧变性与对侧旋转减少有关，而在损伤侧黑质网状部的B区（后部）注射时，与对侧旋转增加有关，与完整侧相比。（2）植入纹状体的胎儿黑质移植可以使黑质网状部A区而非B区的GABA能敏感性变化恢复正常。
