Maternal deprivation in the early versus late postnatal period differentially affects growth and stress-induced corticosterone responses in adolescent rats
Maternal deprivation in the early versus late postnatal period differentially affects growth and stress-induced corticosterone responses in adolescent rats
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DOI：
10.1016/j.brainres.2006.07.088
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发表时间：
2006-10
期刊：
影响因子：
2.9
通讯作者：
Y. Matsumoto;T. Yoshihara;Y. Yamasaki
中科院分区：
文献类型：
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作者：
Y. Matsumoto;T. Yoshihara;Y. Yamasaki
产后早期的周期性母性剥夺（MD）会导致下丘脑-垂体-肾上腺皮质（HPA）轴对各种类型压力的责任发生永久改变。然而，似乎没有报道描述不同条件下定期MD对发育中大鼠生长的影响以及HPA轴对青春期大鼠固定应激的作用。此外，虽然已知体重变化会影响压力责任，但它们在定期MD下的关系尚不清楚。因此，本研究使用了 4 种不同类型的定期 MD：从产后 (P)1 到 P6（12E 组）每天 12 小时；每天 3 小时，从 P1 到 P6（3E 组）；每天 12 小时，从 P16 到 P21（12L 组）；每天 3 小时，从 P16 到 P21（3L 组）。直到至少 9 周龄，3E 和 12E 组的平均体重均低于对照组，但 3L 和 12L 组的体重增加仅受到短暂影响。 3E 和 12E 组中压力诱导的皮质酮水平直到压力终止后至少 330 分钟才恢复到基础水平，而压力诱导的皮质酮水平的时间变化在 3L、12L 和对照组之间没有显着差异。出生后第一周的定期 MD 会影响发育中大鼠的生长以及青春期大鼠 HPA 轴对固定应激的责任，并且每天 12 小时的 MD 的这种改变程度比每天 3 小时的 MD 更大。相反，从 P16 到 P21 的定期 MD 几乎没有影响。产后定期 MD 会对 HPA 轴的生长和应激反应产生长期影响。此外，存在MD时幼犬的临界年龄以及诱导这些效应的MD的临界长度。
Periodic maternal deprivation (MD) in the early postnatal period leads to permanently altered responsibility of the hypothalamus–pituitary–adrenocortical (HPA) axis to various types of stress. However, no reports appear to have described the effect of periodic MD under different conditions on growth of the developing rat and responsibility of the HPA axis to immobilization stress in adolescent rats. Furthermore, although body weight changes are known to affect stress responsibility, their relationship under periodic MD is not clear. The present study therefore used 4 different types of periodic MD: for 12 h/day from postnatal day (P)1 to P6 (12E group); for 3 h/day from P1 to P6 (3E group); for 12 h/day from P16 to P21 (12L group); and for 3 h/day from P16 to P21 (3L group). Mean body weights were less in the 3E and 12E groups than in the control group until at least 9 weeks old, although body weight gain in the 3L and 12L groups was only transiently affected. Stress-induced corticosterone levels in the 3E and 12E groups did not return to basal levels until at least 330 min after the termination of stress, while temporal variations of stress-induced corticosterone levels did not differ significantly between the 3L, 12L and control groups. Periodic MD in the first postnatal week affected growth of developing rats and responsibility of the HPA axis to immobilization stress in adolescent rats, and the extent of this modification was larger with MD for 12 h/day than with MD for 3 h/day. Conversely, periodic MD from P16 to P21 had little effect. Periodic MD in the postnatal period induces long-term effects on growth and stress responsibility of the HPA axis. Furthermore, a critical age of the pup at the time of MD exists as well as a critical length of MD for inducing these effects.