Some studies have reported that MS induces impaired memory ( 8), anxiety, and depressive behavior in rodents ( 9, 10). However, due to the different MS paradigms and strains, the findings of the animal behavioral changes in both mice and rats are inconsistent. Considering the importance of mother–infant attachment in the early-life period, maternal separation (MS) is one of the most widely used models to elucidate the effects and neurobiological mechanisms of child neglect ( 7). It is well-known that child neglect increases the risk for the development of many psychiatric disorders, including anxiety disorder, post-traumatic stress disorder (PTSD), and depression ( 5, 6). The developing brain is particularly sensitive to early-life neglect. The number of left-behind children has been increasing dramatically in recent decades in China ( 4). In addition, MSEW induced adaptive modification, which depended on a non-stressful context.Ĭhild neglect is the most common form of early-life stress in both Western and Eastern countries ( 1– 3). The reduced glutamatergic neuronal excitability may be associated with the emotional alteration induced by MSEW in male rats. Our findings showed that MS with early weaning induced anxiety-like behavior in male rats. MSEW reduced the number of glutamatergic neuron APs in male rats. MSEW slightly impaired working memory during non-stressful situations in female rats but did not change spatial reference memory or associative learning under stressful circumstances in either sex. MSEW resulted in anxiety-like behavior, a passive coping strategy and increased fear memory in male rats and decreased locomotor activity in both sexes. The action potentials (APs) of glutamatergic neuronal membranes were recorded. A battery of behavioral tests was used to assess anxiety-like behavior, coping behavior, working memory, spatial reference memory, and fear memory. Rats were separated from the dam for 4 h per day on postnatal days (PNDs) 2–5 and for 8 h per day on PNDs 6–16 and then weaned on PND 17. An MS with early weaning (MSEW) rat model was developed. This study aimed to develop a reliable child neglect rat model and observe glutamatergic neuronal excitability in the PFC. No studies to date have examined the impact of early-life stress on glutamatergic neuronal excitability in the PFC. The prefrontal cortex (PFC) integrates information from many cortical and subcortical structures. Accumulating evidence shows that neuronal intrinsic excitability plays an important role in information processing and storage in the brain. Difficulties in developing reliable child neglect models have impeded advances in identifying the effects of early-life stress. However, reports have shown considerable variability in behavioral results from MS studies in both mice and rats. Maternal separation (MS) has been commonly used as a rodent model to identify the developmental effects of child neglect.
2Peking Union Medical College, Institute of Medicinal Plant Development, Chinese Academy of Medical Science, Beijing, ChinaĮarly-life neglect in critical developmental periods has been associated with emotional and cognitive consequences.1National Health Commission Key Laboratory of Human Disease Comparative Medicine, Beijing Engineering Research Center for Experimental Animal Models of Human Critical Diseases, Institute of Laboratory Animal Science, Chinese Academy of Medical Science (CAMS) & Peking Union Medical College (PUMC), Beijing, China.Xiuping Sun 1 †, Yu Zhang 1 †, Xianglei Li 1, Xinmin Liu 2 and Chuan Qin 1 *