Ossenkopp K P, Sutherland C, Ladowsky R L
Pharmacol Biochem Behav. 1986 Jul;25(1):269-76. doi: 10.1016/0091-3057(86)90265-0.
Three experiments examined the effects of centrally and peripherally acting scopolamine (scopolamine hydrochloride-SHC) or only peripherally acting scopolamine (scopolamine methyl nitrate-SMN), on motor activity levels and the ability of these agents to induce taste aversions. In Experiment 1 rats were injected with isotonic saline, 1 mg/kg SHC, or 1 mg/kg SMN. SHC produced significant increases in stabilimeter activity (p less than 0.025) and in rearing response frequency (p less than 0.01), whereas SMN resulted in significantly less activity (p less than 0.025). Both agents induced strong conditioned taste aversions to saccharin (p less than 0.01). Experiment 2 examined the role of the area postrema in mediating these drug induced behavioral changes. Sham lesioned and area postrema lesioned rats were given saline, SHC or SMN (1 mg/kg for both drugs) and examined for changes in activity, rearing response frequency and induction of taste aversions to saccharin. SHC again produced significant increases in activity (p less than 0.01), whereas SMN produced decrements in activity (p less than 0.05). However, the brain lesion did not consistently alter the effects of these drugs on activity but it did reduce the amount of the decrement observed in rearing responses in SMN treated rats. The brain lesion also altered the ability of the drugs to induce taste aversions. Both SMN and SHC produced strong taste aversions in the sham lesioned rats (p less than 0.01) but no significant aversions were observed in the area postrema lesioned rats. Experiment 3 examined the ability of the brain lesion to alter the effects of SMN by using a within groups design. Area postrema lesions were found to attenuate but not abolish, the inhibitory effects of SMN on both activity levels and rearing responses (p less than 0.03). The results of these experiments suggest that in the absence of the chemically-sensitive area postrema both SMN and SHC fail to induce taste aversions and the inhibitory effect of SMN on spontaneous activity is attenuated.
三项实验研究了中枢和外周作用的东莨菪碱（氢溴酸东莨菪碱-SHC）或仅外周作用的东莨菪碱（硝酸甲基东莨菪碱-SMN）对运动活动水平的影响以及这些药物诱导味觉厌恶的能力。在实验1中，给大鼠注射等渗盐水、1mg/kg的SHC或1mg/kg的SMN。SHC使稳定计活动显著增加（p<0.025），并使竖毛反应频率显著增加（p<0.01），而SMN导致活动显著减少（p<0.025）。两种药物均诱导对糖精产生强烈的条件性味觉厌恶（p<0.01）。实验2研究了最后区在介导这些药物诱导的行为变化中的作用。给假损伤和最后区损伤的大鼠注射盐水、SHC或SMN（两种药物均为1mg/kg），并检测其活动、竖毛反应频率的变化以及对糖精味觉厌恶的诱导情况。SHC再次使活动显著增加（p<0.01），而SMN使活动减少（p<0.05）。然而，脑损伤并未始终改变这些药物对活动的影响，但确实减少了在接受SMN治疗的大鼠中观察到的竖毛反应减少量。脑损伤还改变了药物诱导味觉厌恶的能力。SMN和SHC在假损伤大鼠中均产生强烈的味觉厌恶（p<0.01），但在最后区损伤的大鼠中未观察到显著的厌恶反应。实验3采用组内设计研究了脑损伤改变SMN作用的能力。发现最后区损伤可减弱但并未消除SMN对活动水平和竖毛反应的抑制作用（p<0.03）。这些实验结果表明，在没有化学敏感的最后区时，SMN和SHC均无法诱导味觉厌恶，且SMN对自发活动的抑制作用减弱。
