Laboratory of Physiology, São Paulo State University, São Paulo, Brazil.
J Psychopharmacol. 2010 May;24(5):725-31. doi: 10.1177/0269881109106954. Epub 2009 Nov 25.
The present work aimed to evaluate the effects of social separation for 14 days (chronic stress) and of withdrawal from a 14-day treatment with diazepam (acute stress) on the exploratory behaviour of male rats in the elevated plus-maze and on serotonin (5-hydroxytryptamine) turnover in different brain structures. Social separation had an anxiogenic effect, evidenced by fewer entries into, and less time spent on the open arms of the elevated plus-maze. Separation also selectively increased 5-hydroxytryptamine turnover in the hippocampus and median raphe nucleus. Diazepam withdrawal had a similar anxiogenic effect in grouped animals and increased 5-hydroxytryptamine turnover in the same brain structures. Chronic treatment with imipramine during the 14 days of separation prevented the behavioural and neurochemical changes caused by social separation. It is suggested that the increase in anxiety determined by both acute and chronic stress is mediated by the activation of the median raphe nucleus-hippocampal 5-hydroxytryptamine pathway.
本研究旨在评估社交分离 14 天（慢性应激）和 14 天苯二氮䓬治疗后停药（急性应激）对雄性大鼠在高架十字迷宫中的探索行为以及不同脑结构中 5-羟色胺（5-羟色胺）代谢产物的影响。社交分离产生焦虑作用，表现为进入高架十字迷宫开放臂的次数减少，在开放臂上花费的时间减少。分离还选择性地增加了海马体和中缝核中的 5-羟色胺代谢产物。在分组动物中，苯二氮䓬停药也具有类似的致焦虑作用，并增加了相同脑结构中的 5-羟色胺代谢产物。在分离的 14 天中慢性给予丙咪嗪治疗可预防社交分离引起的行为和神经化学变化。这表明，急性和慢性应激引起的焦虑增加是由中缝核-海马 5-羟色胺通路的激活介导的。
