哺乳动物后代如果在子宫中发育时缺乏某些荷尔蒙，那么当它们成年时就更有可能产生焦虑。在本期Nature Communications上报告的这些发现让我们对胎盘在情绪行为的长期编程中所起作用有了新认识。
“胰岛素样生长因子-2”曾被发现在哺乳动物的胎儿和胎盘发育中扮演一个主要角色，而且这种荷尔蒙在胎盘和胎儿中的表达的变化也被发现与子宫中的生长限制有关。虽然子宫内的生长限制已知影响新生儿的发育，但其长期后果却并不完全清楚。Lawrence Wilkinson及其同事研究了仅在胎盘中缺少“胰岛素样生长因子-2”的小鼠的成年行为，发现这些小鼠与焦虑有关的行为特征增加，同时伴随着脑中与这种行为有关的基因表达的特定变化。
虽然这些研究是用小鼠完成的，但这些发现对人类发育可能会有更广泛的意义。然而，还需要进一步的研究来确定这一猜测在多大程度上是正确的。（生物谷 Bioon.com）
生物谷推荐的英文摘要
Nature Communications doi:10.1038/ncomms3311
Placental programming of anxiety in adulthood revealed by Igf2-null models
Mikael Allan Mikaelsson, Miguel Constância, Claire L. Dent, Lawrence S. Wilkinson & Trevor Humby
Imprinted, maternally silenced insulin-like growth factor-2 is expressed in both the foetus and placenta and has been shown to have roles in foetal and placental development in animal models. Here we compared mice engineered to be null for the placenta-specific P0 transcript (insulin-like growth factor-2-P0 KO) to mice with disruptions of all four insulin-like growth factor-2 transcripts, and therefore null for insulin-like growth factor-2 in both placenta and foetus (insulin-like growth factor-2-total KO). Both models lead to intrauterine growth restriction but dissociate between a situation where there is an imbalance between foetal demand and placental supply of nutrients (the insulin-like growth factor-2-P0 KO) and one where demand and supply is more balanced (the insulin-like growth factor-2-total KO). Increased reactivity to anxiety-provoking stimuli is manifested later in life only in those animals where there is a mismatch between placental supply and foetal demand for nutrients during gestation. Our findings further distinguish placental dysfunction from intrauterine growth restriction and reveal a role for the placenta in long-term programming of emotional behaviour.
