Crawley J N
Pharmacol Biochem Behav. 1984 Jan;20(1):23-7. doi: 10.1016/0091-3057(84)90094-7.
Cholecystokinin (CCK8), an octapeptide present in high concentrations in both gut and brain, has been proposed as a putative satiety signal in a variety of species. Exploratory and social behaviors in particular are inhibited by exogenously administered CCK8. One hypothesis for the mechanism by which CCK reduces feeding and exploration is that CCK8 is reducing arousal and attention to environmental stimuli. This possibility was tested by analyzing the rate of habituation to the novelty of objects placed in an unfamiliar arena. A video-tracking computer-assisted animal behavior monitor measured four parameters of exploratory behaviors in rats pretreated with intraperitoneal CCK8. During the first 30 minutes in the novel environment, CCK8-treated animals showed a reduced latency to cessation of exploration as compared to saline controls. In repeated five minute sessions on consecutive days, CCK8 treatment accelerated the decline in exploration over daily sessions. Pentobarbital, a known sedative, induced low levels of exploration throughout the repeated daily sessions. These data suggest that CCK8 is inducing a more rapid rate of habituation to the novelty of environmental stimuli. An accelerated rate of habituation might underlie some of the satiety-related behavioral effects of this peptide.
胆囊收缩素（CCK8）是一种在肠道和大脑中均高浓度存在的八肽，已被认为是多种物种中一种假定的饱腹感信号。特别是外源性给予CCK8会抑制探索行为和社交行为。关于CCK减少进食和探索的机制的一种假设是，CCK8正在降低对环境刺激的唤醒和注意力。通过分析对放置在陌生场地中的新物体的习惯化速率来检验这种可能性。一台视频跟踪计算机辅助动物行为监测仪测量了经腹腔注射CCK8预处理的大鼠探索行为的四个参数。在新环境中的最初30分钟内，与生理盐水对照组相比，接受CCK8处理的动物停止探索的潜伏期缩短。在连续几天每天进行的五分钟重复实验中，CCK8处理加速了每日实验中探索行为的下降。戊巴比妥是一种已知的镇静剂，在每日重复实验中均诱导出低水平的探索行为。这些数据表明，CCK8正在诱导对环境刺激新奇性的更快习惯化速率。习惯化速率加快可能是该肽一些与饱腹感相关的行为效应的基础。
