Division of Psychology, Graduate School of Letters, Hokkaido University, Kita 10, Nishi 7, Kita-Ku, Sapporo 060-0810, Japan.
Division of Psychology, Graduate School of Letters, Hokkaido University, Kita 10, Nishi 7, Kita-Ku, Sapporo 060-0810, Japan.
Neurotoxicology. 2018 Dec;69:29-36. doi: 10.1016/j.neuro.2018.08.006. Epub 2018 Aug 29.
Rat pups produce ultrasonic vocalizations (USVs) on isolation from their dam. Ultrasonic vocalization is a sensitive tool for evaluating social behavior between pups and their dam. Prenatal ethanol-exposure leads to a reduction in USVs and have the potential of inducing difficulties in social behavior between pups and their dam. However, effects of prenatal ethanol-exposure on the acoustic characteristics of USVs remain unclear. In this study, we recorded USVs produced by rat pups that were prenatally exposed to ethanol and examined their acoustic characteristics. Ethanol was administered to 13 pregnant rats in three stages by gradually increasing concentrations between gestational days (GDs) 8-20. From GDs 14-20, ethanol-containing tap water at concentrations of 30% and 15% (v/v) was administered to the high- and low-ethanol groups, respectively. Tap water without ethanol was given to the control group. On postnatal days (PNDs) 4, 8, 12, and 16, individual newly-born pups were isolated from their dam and littermates and USVs produced by them were recorded for 5 min. The number of USVs in the high-ethanol group was greater than that in both low-ethanol and control groups on PND 12. The mean, minimum, and maximum fundamental frequencies of USVs were elevated in the high-ethanol group compared with that in both low-ethanol and control groups. Higher amplitudes of USVs were produced by male pups in the high-ethanol group than in those in both low-ethanol and control groups on PND 12. These results suggest that prenatal ethanol exposure changed emotionality and accordingly, the high-ethanol group produced more USVs as distress calls.
幼鼠在与母鼠隔离时会发出超声波叫声（USVs）。超声波叫声是评估幼鼠与其母鼠之间社会行为的敏感工具。产前乙醇暴露会导致 USVs 减少，并有可能导致幼鼠与其母鼠之间的社会行为出现困难。然而，产前乙醇暴露对 USVs 的声学特征的影响尚不清楚。在这项研究中，我们记录了产前暴露于乙醇的幼鼠发出的 USVs，并检查了它们的声学特征。在妊娠第 8-20 天，通过逐渐增加浓度，将乙醇分三个阶段给予 13 只怀孕的大鼠。从妊娠第 14-20 天开始，高浓度组和低浓度组分别给予含有 30%和 15%（v/v）乙醇的自来水，对照组给予不含乙醇的自来水。在出生后第 4、8、12 和 16 天，将每个新生幼鼠与其母鼠和同窝幼鼠隔离，并记录它们发出的 USVs 5 分钟。在第 12 天，高浓度组的 USVs 数量多于低浓度组和对照组。与低浓度组和对照组相比，高浓度组 USVs 的平均频率、最小频率和最大频率均升高。在第 12 天，雄性幼鼠在高浓度组产生的 USVs 幅度高于低浓度组和对照组。这些结果表明，产前乙醇暴露改变了幼鼠的情绪，因此，高浓度组产生了更多的 USVs，作为痛苦的叫声。
