Swerdlow N R, Koob G F
Department of Psychiatry, School of Medicine, University of California, San Diego, La Jolla 92093.
Pharmacol Biochem Behav. 1989 Jul;33(3):595-9. doi: 10.1016/0091-3057(89)90394-8.
Intraventricular (ICV) infusion of norepinephrine (NE) produces locomotor activation in rats that is greatly potentiated by prior depletion of whole brain catecholamines by ICV injection of 6-hydroxydopamine (6OHDA). In a series of experiments, the neural substrates of this potentiated locomotor response were examined. One group of animals received ICV infusion of 6OHDA to deplete whole brain catecholamines. Other rats were pretreated with desmethylimipramine (DMI) and then received 6OHDA infusions into the nucleus accumbens (NAC) to selectively deplete dopamine (DA) from this region. One week later, all animals were tested for their locomotor response to ICV infusion of NE. Both groups of rats exhibited a greatly potentiated locomotor response to ICV NE compared to corresponding sham-lesioned animals. Both ICV and NAC 6OHDA-injected animals also exhibited a supersensitive locomotor response to the DA receptor agonist apomorphine. These results suggest that NE-induced locomotor activation in ICV 6OHDA-treated rats results from the actions of NE on supersensitive NAC DA receptors.
脑室内(ICV)注射去甲肾上腺素(NE)可使大鼠产生运动激活,而预先通过脑室内注射6-羟基多巴胺(6OHDA)耗尽全脑儿茶酚胺会极大地增强这种激活作用。在一系列实验中,研究了这种增强的运动反应的神经基础。一组动物接受脑室内注射6OHDA以耗尽全脑儿茶酚胺。其他大鼠先用去甲丙咪嗪(DMI)预处理,然后将6OHDA注入伏隔核(NAC)以选择性地耗尽该区域的多巴胺(DA)。一周后,测试所有动物对脑室内注射NE的运动反应。与相应的假损伤动物相比,两组大鼠对脑室内注射NE均表现出极大增强的运动反应。脑室内和伏隔核注射6OHDA的动物对DA受体激动剂阿扑吗啡也表现出超敏运动反应。这些结果表明,在脑室内注射6OHDA处理的大鼠中,NE诱导的运动激活是由于NE对超敏的伏隔核DA受体的作用所致。