Wilkin Meaghan M, Waters Pattti, McCormick Cheryl M, Menard Janet L
Department of Psychology, Queen's University, 62 Arch Street, Kingston, ON, USA.
Behav Neurosci. 2012 Apr;126(2):344-60. doi: 10.1037/a0027258. Epub 2012 Feb 20.
Prior work showed that exposing rats to stress from weaning through to late adolescence (PD23-51) increased anxiety- and depression-related responses in adulthood. In the current study, we tested the hypothesis that the outcome of adolescent stress depends on the specific timing of adversity in adolescence. Male and female rats were exposed to intermittent, physical stress during either early (PD22-33) or mid -(PD35-46) adolescence, and then their anxiety- and depression-related responses to acute stressors were tested in adulthood. Early adolescent stress decreased rats' open-arm exploration in the elevated plus-maze in both male and female rats. Early adolescent stress also increased the duration of time rats spent burying in the shock-probe test and the duration of time they spent immobile in the forced swim test, but these effects were only seen in males. Stress in mid-adolescence did not increase rats' anxiety-related responding in adulthood. Instead, we observed paradoxical increases in open-arm exploration and only modest increases in shock-probe burying that failed to reach significance. Mid-adolescent stress also tended to increase depression-related immobility in the swim test. Thus, the current findings underscore the importance of timing of adolescent adversity to long-term outcomes. It appears that stress in early adolescence leads to a broader range of outcomes in adulthood, at least in male rats. By contrast, stress in mid-adolescence might have more predominant effects on risk-taking behavior (indexed by increases in open-arm activity), a possibility that merits further investigation.
先前的研究表明，从断奶到青春期后期（出生后第23 - 51天）让大鼠处于应激状态会增加其成年后与焦虑和抑郁相关的反应。在当前的研究中，我们检验了这样一个假设，即青少年期应激的结果取决于青春期逆境的具体时间。雄性和雌性大鼠在青春期早期（出生后第22 - 33天）或中期（出生后第35 - 46天）接受间歇性身体应激，然后在成年期测试它们对急性应激源的焦虑和抑郁相关反应。青春期早期应激减少了雄性和雌性大鼠在高架十字迷宫中的开臂探索。青春期早期应激还增加了大鼠在电击探针测试中埋土的持续时间以及在强迫游泳测试中静止不动的持续时间，但这些影响仅在雄性大鼠中可见。青春期中期应激在成年期并未增加大鼠的焦虑相关反应。相反，我们观察到开臂探索出现了反常增加，电击探针埋土仅有适度增加且未达到显著水平。青春期中期应激在游泳测试中也倾向于增加与抑郁相关的静止不动。因此，当前的研究结果强调了青春期逆境时间对长期结果的重要性。似乎青春期早期应激会导致成年期出现更广泛的结果，至少在雄性大鼠中是这样。相比之下，青春期中期应激可能对冒险行为（以开臂活动增加为指标）有更主要的影响，这一可能性值得进一步研究。
