Staunton D A, Young S J, Groves P M
Brain Res. 1980 Apr 21;188(1):107-17. doi: 10.1016/0006-8993(80)90560-0.
Spontaneously active neurons from the pars compacta region of the substantia nigra were studied in chloral hydrate anesthetized, immobilized rats which had been pretreated with daily intraperitoneal saline or D-amphetamine injections according to several schedules. The spontaneous firing rates of these neurons were not altered by any of the pretreatment regimens. In addition, the intravenous dose of D-amphetamine sulfate which was required to reduce the spontaneous firing rate of these cells by at least 50% (threshold dose) was not modified by amphetamine pretreatment. There was a significant positive linear correlation between the threshold dose and the initial spontaneous firing rate of the neurons from animals pretreated with multiple saline injections, but not from those receiving long-term D-amphetamine. These results demonstrate that there are no alterations in the sensitivity of dopaminergic neurons to amphetamine under conditions known to produce the enhanced effects of the drug on motor behaviors which develop during multiple injections.
在水合氯醛麻醉、固定的大鼠中研究了黑质致密部区域的自发放电神经元，这些大鼠根据几种给药方案每日接受腹腔注射生理盐水或右旋苯丙胺预处理。这些神经元的自发放电率未因任何预处理方案而改变。此外，将这些细胞的自发放电率降低至少50%（阈剂量）所需的硫酸右旋苯丙胺静脉注射剂量并未因苯丙胺预处理而改变。在多次注射生理盐水预处理的动物中，阈剂量与神经元的初始自发放电率之间存在显著的正线性相关，但在长期接受右旋苯丙胺的动物中则不存在。这些结果表明，在已知会产生该药物对多次注射期间出现的运动行为增强作用的条件下，多巴胺能神经元对苯丙胺的敏感性没有改变。
