Detour behavior changes associated with prenatal morphine exposure in 11-day-old chicks

The central nervous system exhibits remarkable plasticity in early life. Prenatal morphine exposure may induce adverse behavioral effects on the neonate and the developing offspring. In the present study, we investigated the effect of prenatal morphine exposure (daily from embryonic days 12-16, 20 mg/kg) on 11-day-old chicks using two forms of spatial paradigms: one trial detour behavior task in which animals must bypass an obstacle to reach the desired goal without any training and detour learning task which required several trials of training to reach the detour criterion. The results showed that, on the condition that chicks could successfully detour in the first trial, morphine exposed chicks exhibited longer detour latency to finish the task, coupled by a preference for turning right versus turning left. In contrast, no significant difference in learning and memory was found in detour learning task between morphine exposed chicks and saline chicks. These findings suggest specific behavioral changes associated with prenatal exposure to opioids during mid to late gestation, also raise attention to the possible health hazard from pregnancy drug use in everyday life. (C) 2010 ISDN. Published by Elsevier Ltd. All rights reserved.

社会冲突信息加工的事件相关电位研究

Processing of discrepant information is an important part in our everyday life. According to the social attributes of information, it can be categorized into two parts: social discrepancy and nonsocial discrepant information. The researches focused on nonsocial discrepancy are much mature than those of social discrepancy processing. This serial study employed three ERP experiments to explore the attributes of social discrepancy cognition. Experiment one compared the ERP differences between social and nonsocial discrepancy processing, experiment two adopted single stimulus paradigm to explore the negativity attention biases of social emotions, experiment three investigated the affective mechanism of emotions to social discrepancy information with cue-target paradigm, based on the experiment one and two. We invited healthy undergraduates to participate in our researches, in which social gender words and affective images were stimuli to explore the temporal sequences, activated modes and affective mechanisms of social discrepancy. The results were as below: 1. The differences of attention resource distributions between social and nonsocial information processing exhibited as early as 200 ms, since which P2 was evoked in both blocks. The larger P2 in nonsocial block represented the more attention to physical and nonsocial attributes of objects. N300/400 indicated the differences of evaluating systems in each block. The cognitive mechanisms of social and nonsocial tasks were specific, based on the fact: (1) the discrepancy evaluating system was activated earlier in nonsocial block than that of social block; (2) the social cognition performed right hemisphere advantage, but nonsocial task did not so. 2. Social emotions also could raise a negativity bias on attention. The latency of P2 evoked by social sad images was shorter than that of social happiness and neutral images. The latencies of P2 indicated that sad emotions attracted attention earlier, and possessed a processing advantage. The phenomenon that the larger N2 was evoked by social sadness showed that people was easily moved by sad emotions and sympathized the sadness. 3. Emotions affected social discrepancy processing. Positive affective mood magnified the discrepancy effect, based on the smaller latencies of difference N400 and larger amplitudes. Persons with happy mood synthesized social stereotypes to accelerate the social tasks. 4. Three experiments all showed the right hemisphere advantages of social cognition and social emotions, offered more proof in laterality hypothesis of social cognition. Above all, social cognition had essential distinctions with nonsocial cognition; they two had their own specific characteristics. The fact that social cognition was prone to be affected by different emotional mood made it more complex.