Behavioral and Physiolosical Characteristics of the Animal Model of Mental Retardation (Fetal Alcohol Syndrome)

点击翻译按钮获取中文摘要

This study aimed to elucidate the effects of prenatal alcohol exposure on circadian activity rhythms, passive avoidance learning, and rhythmic activity of hippocampal EEG in the rat. Subjects were female albino rats of the Wistar-Imamichi strain and their offspring. Female rats of experimental group were administered 6% alcohol solution ad libitum as the sole fuluid source during 0-18 days of gestation, while after these treatment, mother rats and also their offspring were provided with water. Control rats were provided with water ad libitum throuthout the experiment. Activity test was performed with 8 pups in each group under the LD12 : 12 condition and then under the DD condition during 21-85 days after birth. Alcohol-exposed offspring were more active throughout the experiment than control offspring. Re-entrainment of circadian rhythms after 6 hours advanced or delayd phase-shifts of the LD12 : 12 illumination could be seen in all offspring in both groups, though alcohol-exposed offspring re-entrained more rapidly after both phase-shifts than control rats. Passive avoidance test was performed with 46 pups in each group, during 10 days from 21, 46, 70 days of age after birth respectively. Alcohol-exposed offspring required more trials for extinction than control offspring. There were no significant differences on activity and on emotionality during retention test traials between two groups, though the incidence of urination in the alcohol-exposed group decreased quickly compared with those in the control group. Hippocampal EEG were recorded monopolarly from 10 offspring in each group during voluntary movements, such as walking, locomotion, realing, head movement and sniffing, and during REM sleep. In the control group, appearances of hippocampal rhythmic slow activity were remarkable during voluntary movements, especially during walking, locomotion and rialing, and also during REM sleep. Alcohol-exposed offspring showed unclear rhythmic slow activity during volun