围产期食物限制对子代成年大鼠海马CA1区突触可塑性的影响

围产期食物限制导致子代大鼠学习和记忆能力等的神经生物学变化，但其机制并不清楚。将成年Wistar雌性大鼠与雄性大鼠同笼，受孕后随机分为对照组 (n=9) 和食物限制组 (n=8) 。对照组母鼠在妊娠期和哺乳期自由进食和饮水，食物限制组母鼠从妊娠的第7天到子代大鼠出生后21天进行食物限制，食物限制量为对照组大鼠的50%。子代雄性大鼠成年后，通过Morris 水迷宫测试空间学习和记忆能力。之后，在海马CA1区在体记录场兴奋性突触后电位 (field excitatory postsynaptic potential，fEPSP)，并采用免疫组织化学方法观察海马CA1区神经元型一氧化氮合酶 (nNOS) 阳性细胞密度的变化。结果表明，围产期食物限制降低了子代大鼠出生后第1、7、10、14和21天的体重，并减弱了成年子代大鼠的学习和记忆能力，海马CA1区fEPSP的斜率和nNOS阳性细胞的密度也明显降低。结果提示，围产期食物限制可能通过抑制NO的产生降低了海马突触可塑性，从而影响了子代大鼠的学习和记忆能力。

Effects of Perinatal Food Restriction on Synapticity in Hippocampal CA1 Area in Adult Offspring Rats

Perinatal food restriction induces neurobiological changes, including deficiency in learning and memory, in rat offspring. However, the mechanism is still unclear. The females were paired with the males. Afterwards, the pregnant rats were assigned radomly into two groups: the control group and the model group. In the control group (n=9), dams had free access to diet and water during gestation and lactation. In the model group, dams (n=8) received 50% of the daily food intake of control mothers from gestation day 7 until the postnatal day 21. Spatial learning and memory ability was tested in Morris water maze in adult offspring rats. Afterwards, the in vivo field excitatory postsynaptic potential (fEPSP) was observed in the hippocampal CA1 area. In addition, the density of nNOS neurons in hippocampal CA1 area was recorded using immunohistochemistry. The results showed that the perinatal food restriction reduced body weight of offsprings on postnatal day (PD)1, PD7, PD10, PD14 and PD21, and impaired learning and memory of adult male offspring rats. This type of food restriction also decreased fEPSP slope of long-term potentiation (LTP) in hippocampal CA1 area. Importantly, the density of nNOS positive cells in hippocampal CA1 area was decreased by this type of food restriction. These findings suggested that perinatal food restriction impaired synaptic plasticity by reducing the product of NO in hippocampal CA1 area, and induced learning and memory disturbances in offspring rats.