Department of Neuroscience and Physiology, SUNY Upstate Medical University, 750 East Adams Street, Syracuse, NY 13210, United States.
Behav Brain Res. 2011 Jan 1;216(1):358-64. doi: 10.1016/j.bbr.2010.08.014. Epub 2010 Aug 20.
During development of the central nervous system, neurons pass through critical periods of vulnerability to environmental factors. Exposure to ethanol during gastrulation or during neuronal generation results in a permanent reduction in the number of neurons in trigeminal-associated cranial nerve nuclei. Normal functioning of the trigeminal system is required for social behavior, the present study examined the effects of acute prenatal exposure to ethanol on social interactions across ontogeny. Pregnant Long-Evans rats were injected with 2.9 g/kg ethanol (i.p., 20%, v/v solution; peak blood ethanol concentrations of ∼300 mg/dl) or an equivalent volume of saline on gestational day (G) 7 (gastrulation) or G12 (neuronal generation). Subsequently, social investigation, play fighting, contact behavior, social motivation, and overall locomotor activity in the social context were assessed in male and female off-spring during early adolescence, late adolescence, or adulthood, on postnatal day (P) 28, P42, or P75, respectively, using a modified social interaction test. Ethanol exposure on G7 resulted in mild changes of social behavior evident in young adolescents only. In contrast, animals exposed to ethanol on G12 demonstrated pronounced behavioral deficits throughout ontogeny, with deficits being most robust in male off-spring. Males exposed to ethanol on G12 showed decreases in social investigation, contact behavior, and play fighting, whereas a decrease in social motivation, i.e., transformation of social preference into social avoidance, was evident at P42 and P75 regardless of sex. These findings show that acute exposure to ethanol alters social behavior, and that the timing of the exposure defines the behavioral outcome.
在中枢神经系统发育过程中，神经元会经历对环境因素敏感的关键时期。在原肠胚形成期或神经元发生期暴露于乙醇会导致三叉神经相关颅神经核中神经元数量永久减少。三叉神经系统的正常功能是社交行为所必需的，本研究检查了急性产前暴露于乙醇对跨个体发生期社交互动的影响。在妊娠第 7 天（原肠胚形成期）或第 12 天（神经元发生期），给怀孕的 Long-Evans 大鼠腹腔内注射 2.9 g/kg 乙醇（i.p.，20%，v/v 溶液；血乙醇峰值浓度约为 300 mg/dl）或等量的生理盐水。随后，在雄性和雌性后代的早期青春期、晚期青春期或成年期（出生后第 28、42 或 75 天），使用改良的社交互动测试，分别评估社交调查、玩耍格斗、接触行为、社交动机和社交环境中的总体运动活动。在 G7 时暴露于乙醇会导致仅在青少年早期表现出轻微的社交行为变化。相比之下，在 G12 时暴露于乙醇的动物在整个个体发生期表现出明显的行为缺陷，雄性后代的缺陷最为明显。在 G12 时暴露于乙醇的雄性后代表现出社交调查、接触行为和玩耍格斗减少，而社交动机减少，即社交偏好转化为社交回避，在 P42 和 P75 时无论性别均明显。这些发现表明，急性暴露于乙醇会改变社交行为，而暴露的时间决定了行为结果。
