Toxicity Effects On Spatial Memory And Rela Tedbrain Region Morphology In Adolescence And Adul Tmouse: Treated With Low Concentration Chlorpyrifos In Late Prena Talperiod

Chlorpyrifos (chlorpyrifos, CPF) is a high residue ofOrganophosphorus pesticides in the production and widely used in life. Inrecent years, CPF elicits the concern of scientists with itsneurodevelopmental toxicity. The purpose of this study is to reveal theeffects of low dose CPF exposure at late pregnant dams on spatialmemory and related brain morphology in adolescence and adulthoodmice offsprings. Gestation day (GD 13) ICR mice were randomlydivided into 3 groups. CPF dissolved in dimethyl sulfoxide wasadministered by gavage at doses of 0, 1 mg/(kg·d), 5 mg/(kg·d) forcontinuous 5 days from GD 13-17. On postnatal day (PD 35), we began to take T-maze delay alternation test. Mice were divided into six groupsdependent on CPF dosage and sex, with 8 male or female for each group.Number of reaction accuracy, win-shift error and lose-shift error at delaytime 0s,10s,20s,40s and 60s were recorded and analysis. After finishedthe T-Maze delay alternation test, we dissected the male mice of controland 5 mg/(kg·d) group, and picked up the brain tissue of mice for analysethe morphology of brain zone. We Compared the changes ofHippocampus cell structure by general paraffin embedded method and HEstaining.It was found no difference that either female or male mice in the Tmazedelay alternation experiment with different delay time accuracy,Regardless male or female of 1mg/kg dosage group and the control groupin the Win-shift and the Lose-shift frequency of the error types, there is nosignificant difference. 5 mg/(kg·d) dose group of female mice and thecontrol group in the Win-shift error also have no obvious change, but inthe Lose-shift error times of the delay time of 10s, compared with thecontrol group were significantly increased. 5 mg / (kg ? d) dose groupscompared with the control group of male mice, Win-shift type error hasno significant change, but when the delay time increased Lose-shift errornumbers in the 40s and 60s significantly increases as well. Weadminisitrated these brain with HE staining by general paraffin embeddedmethod to analyse the cell morphology and structure of involving spatial memory such as the prefrontal cortex and hippocampus. Morphologicalanalysis of brain cells found that 5 mg / (kg ? d) doses of hippocampusCA1 area and CA3 area of the cell layers are less than the control group,while the DG area of the cell layers are more than the control group.