Costa Rafaela, Tamascia Mariana L, Nogueira Marie D, Casarini Dulce E, Marcondes Fernanda K
Laboratory of Stress, Physiological Sciences Division, Piracicaba Dental School, University of Campinas (UNICAMP), Piracicaba, Brazil.
J Am Assoc Lab Anim Sci. 2012;51(5):548-53.
Some environmental interventions can result in physiologic and behavioral changes in laboratory animals. In this context, the handling of adolescent or adult rodents has been reported to influence exploratory behavior and emotionality. Here we examined the effects of handling on memory and anxiety levels of adolescent rats. Male Sprague-Dawley rats (age, 60 d) were divided into a control group and a handled group, which were handled for 5 min daily, 5 d per week, for 6 wk. During handling bouts, the rat was removed from its cage, placed in the experimenter's lap or on the top of a table, and had its neck and back gently stroked by the experimenter's fingers. During week 6, each rat's anxiety level was evaluated in the elevated plus-maze (EPM) test. Learning and memory were evaluated 48 h later, by measuring escape latency in the elevated plus-maze test. Plasma corticosterone and catecholamine levels were measured also. Norepinephrine levels were lower in the handled rats compared with control animals, with no differences in epinephrine and corticosterone. As compared with the control rats, the handled rats showed increases in the percentage of time spent in the open arms of the test apparatus, percentage of entries into open arms, and number of visits to the end of the open arms and decreases in the latency of the first open arm entry. Escape latency was lower in the handled rats compared with control rats in both the first and second trials. The data obtained suggest that handling decreases anxiety levels and improves learning skills and memory in rats.
一些环境干预可导致实验动物出现生理和行为变化。在此背景下，据报道，对青春期或成年啮齿动物的处理会影响其探索行为和情绪。在此，我们研究了对青春期大鼠进行处理对其记忆和焦虑水平的影响。将雄性斯普拉格-道利大鼠（60日龄）分为对照组和处理组，处理组每周5天，每天处理5分钟，共处理6周。在处理过程中，将大鼠从笼中取出，放在实验者的腿上或桌子上，实验者用手指轻轻抚摸大鼠的颈部和背部。在第6周，通过高架十字迷宫（EPM）试验评估每只大鼠的焦虑水平。48小时后，通过测量高架十字迷宫试验中的逃避潜伏期来评估学习和记忆。同时测量血浆皮质酮和儿茶酚胺水平。与对照动物相比，处理组大鼠的去甲肾上腺素水平较低，肾上腺素和皮质酮水平无差异。与对照大鼠相比，处理组大鼠在试验装置开放臂中停留的时间百分比、进入开放臂的次数百分比以及到开放臂末端的访问次数增加，首次进入开放臂的潜伏期缩短。在第一次和第二次试验中，处理组大鼠的逃避潜伏期均低于对照大鼠。获得的数据表明，对大鼠进行处理可降低其焦虑水平，并提高其学习技能和记忆力。
