Operant-Behavior Tests in Rats Prenatally Exposed to Low Level Methylmercury / 环境与健康杂志

ABSTRACT

Objective To establish the computer controlled operant behavior test system for rats,and to explore the effects of prenatal exposure to low level methylmercury on the ability of learning and memory in rats Methods The Wistar rats were perorally perfused by 0,0.01,0.05,2.00 mg/(kg?d) methylmercury chloride(MMC) during the period from the 6th day to the 9th day after conception respectively.In every dose group,8 offspring aged 10 weeks were randomly selected to be tested by operant behavior test system.The operant performance was measured in automated nocturnal 15 hour session(16∶00~7∶00).The trial pragram Differential Reinforcement of High (DRH) rate and of low (DRL) rate was carried out by a double blind method.The DRH tests required observed animals to press levers frequently,while the DRL test required the subjects to respect a blocking interval after a reinforcement for pressing lever again. Results The performances scores of 3 exposure groups at doses of 0.01,0.05 and 2.00 mg/(kg?d) methylmercury were significantly lower than that of the control group( P