Lau C E, Spear D J, Falk J L
Department of Psychology, Rutgers University, New Brunswick, NJ 08903.
Pharmacol Biochem Behav. 1994 May;48(1):209-15. doi: 10.1016/0091-3057(94)90518-5.
For rats responding on a 3 h FI 4 min FR 20 schedule of food reinforcement, presession SC nicotine doses (0.1-0.8 mg/kg) produced depression in all responding followed by stimulation of FI responding that was dependent upon both time and dose. With daily presession 0.8 mg/kg SC nicotine injections for 9 days, no tolerance to the depressive or stimulatory effects of nicotine occurred. When nicotine solutions were orally self-administered by presession exposure to 3 h of schedule-induced polydipsia, the subsequent FR responding was unaffected, but the degree of FI response stimulation and its duration occurred in a dose-related fashion (1.18-4.10 mg/kg). Prolonged daily sessions of oral nicotine self-administration provide a technique for investigating the effects of chronic exposure to nicotine. The postingestive effects of nicotine reveal stimulatory effects that last for at least 3 h.
对于按3小时固定间隔（FI）、4分钟固定比率（FR）20次的食物强化时间表做出反应的大鼠，在每次实验前皮下注射尼古丁剂量（0.1 - 0.8毫克/千克）会使所有反应受到抑制，随后FI反应受到刺激，且这种刺激取决于时间和剂量。每天在每次实验前皮下注射0.8毫克/千克尼古丁，持续9天，未出现对尼古丁抑制或刺激作用的耐受性。当通过在每次实验前让大鼠接触3小时由时间表诱导的多饮来口服自我给药尼古丁溶液时，随后的FR反应未受影响，但FI反应刺激的程度及其持续时间呈剂量相关方式出现（1.18 - 4.10毫克/千克）。长时间每日进行口服尼古丁自我给药实验提供了一种研究长期接触尼古丁影响的技术。尼古丁的摄入后效应显示出持续至少3小时的刺激作用。
