Institute of Psychopharmacology, Central Institute of Mental Health, Medical Faculty Mannheim/Heidelberg University, J5 68159 Mannheim, Germany.
Institute of Psychopharmacology, Central Institute of Mental Health, Medical Faculty Mannheim/Heidelberg University, J5 68159 Mannheim, Germany.
Behav Brain Res. 2014 May 1;264:143-50. doi: 10.1016/j.bbr.2014.01.046. Epub 2014 Feb 5.
Not all humans become addicted to drugs of abuse following casual use. Thus, it is important to identify factors that may contribute to subsequent drug responding. Previous studies have identified characteristics such as novelty-seeking, impulsivity, and anxiety as factors involved in the progression to drug dependence. The current experiment investigated basal locomotor activity in C57Bl/6N mice as a potential predictor of subsequent nicotine responses. We examined the ability of differences in basal locomotor activity to predict the acute and sensitized response to nicotine, as well as nicotine conditioned reinforcement. A median split was used to distinguish between low and high responders with regard to basal locomotor activity in mice. We then measured the acute response to nicotine (0.5mg/kg IP) in these mice, followed by measures of conditioned place preference (CPP; 0.5mg/kg IP) and locomotor sensitization (0.5mg/kg IP), to determine whether basal locomotion is predictive of subsequent responding to nicotine. High, but not low, basal activity was found to be a predictor of both the acute and sensitized response to nicotine. Interestingly, only mice classified as having low basal activity demonstrated a significant CPP, suggesting that pre-exposure to nicotine differentially affects conditioned reinforcement on the basis of initial activity level. Basal locomotor activity may be an efficient measure of subsequent locomotor responding to nicotine, but only in animals classified as having high basal activity. However, animals with low basal locomotor activity may be more susceptible to the reinforcing properties of nicotine.
并非所有偶然使用药物的人都会上瘾。因此，确定可能导致后续药物反应的因素非常重要。先前的研究已经确定了一些特征，例如寻求新奇、冲动和焦虑，这些都是导致药物依赖的因素。本实验研究了 C57Bl/6N 小鼠的基础运动活动，作为预测随后尼古丁反应的潜在指标。我们研究了基础运动活动差异预测急性和敏化尼古丁反应以及尼古丁条件强化的能力。使用中位数分割来区分小鼠基础运动活动中的低反应者和高反应者。然后，我们测量了这些小鼠对尼古丁（0.5mg/kg IP）的急性反应，随后测量了条件位置偏好（CPP；0.5mg/kg IP）和运动敏化（0.5mg/kg IP），以确定基础运动是否可以预测随后对尼古丁的反应。发现高基础活动而不是低基础活动可预测对尼古丁的急性和敏化反应。有趣的是，只有被归类为具有低基础活动的小鼠表现出明显的 CPP，这表明尼古丁的预先暴露会根据初始活动水平对条件强化产生不同的影响。基础运动活动可能是预测随后对尼古丁运动反应的有效指标，但仅适用于被归类为具有高基础活动的动物。然而，基础运动活动低的动物可能更容易受到尼古丁的强化作用的影响。
