ABSTRACT
Objective To study the effect of sub-chronic exposure to deltamethrin(DM) on the behavior of mice in learning and memory and expression of GABAA receptor α1 and γ2 subunits in the hippocampus of mice.Methods 60 female SPF Kunming mice were randomly divided into solvent control group,low-dose group,middle-dose group and high-dose group, 15 mice in each group.The latter three groups were exposured to deltamethrin for 60 days by gavage.Open field test (OFT) was applied to evaluate locomotor activity and exploratory behavior in mice.RQ-PCR was employed to measure the expression of GABAA receptor α1 and γ2 subunits in hippocampus of mice.Results After exposure to DM,the moving distance of the central area in the middle-dose group ((555.1 ± 12.8) cm) and high-dose group ((516.4± 11.88) cm) was significantly higher than that in the solvent control group ((327.3± 117.8) cm, P＜0.05).Numbers of standing in marginal area (F=4.117, P=0.010) and total movement distance (F=2.914, P=0.042) in the high-dose group ((27.9±9.9) times, (3211.3±379.8) cm) were also significantly higher than that in the solvent control group ((15.1 ±8.9)times, (3211.3±379.8)cm).The expression of GABAA receptor α1 subunit mRNA in the middle-dose group and high-dose group was significantly lower than that in the low-dose group and solvent control group(F=8.508, P=0.001) and the expression of GABAA receptor γ2 subunit mRNA in high-dose group was significantly lower than that in the other groups (F=6.738, P=0.002).Conclusion Sub-chronic exposure to DM can damage the function of locomotor activity and exploratory behavior,and inhibit the expression of GABAA receptor α1 and γ2 subunits in the hippocampus of mice.
ABSTRACT
Objective To study the effect of sub-chronic exposure to dehamethrin(DM) on the behavior of mice in learning and memory.Methods 60 Female SPF Kunming mice were randomly divided into 4 groups and given DM by gavaging for 60 days.Morris water maze (MWM) was used to evaluate spatial memory in mice.Results After exposure to DM,the escape latency of the solvent control group and the treatment groups were (12.20±6.5)s,(14.99±5.4) s,(15.64±8.3)s,(22.71±6.2)s on the fifth day.The escape latency of the high-dose group was higher than those of the low-dose group (P=0.0041) and the solvent control group (P=0.019) in the navigation test.The number of crossing position of the platform in the high-dose group ((2.93± 1.53)times) and the middle-dose group ((3.40± 1.12) times) were lower than that in the solvent control group ((5.87 ± 1.55) times) and the low-dose group ((4.90± 1.41)times)(P＜0.05).Conclusion Sub-chronic exposure to DM can damage the spatial learning and memory of mice.
ABSTRACT
ObjectiveTo study the effect of sub-chronic exposure to deltamethrin(DM) on neural behavior and expression of NMDA receptor in hippocampus of mice.Methods 60 Female SPF Kunming mice were divided into 4 groups and given DM 60 days by gavage.Hot-plate,rotarod,grip strength,hing limb landing foot splay were used to examine the sensory and motor change of mice.Autonomic activity test was used for detecting the functional status of the central nervous system in mice.Passive avoidance test for detection of the behavior changes of learning and memory,and RQ-PCR was employed to measure the expression of NMDA receptor in hippocampus of mice.ResultsThe behavior of sensory and motor of mice sub-chronic exposure to deltamethrin did not have changes significantly(P ＞ 0.05 ).In the test of autonomic activity test,the average of autonomic activity times were (93 ± 18) times,(107 ± 13) times,(105 ±22) times.Compared with the control group,the average of autonomic activity times in middle-and high-dose groups were increased significantly (P ＜ 0.05 ).The latent periods in poisoning groups were (175.4 ±38.4) s,(146.4 ±51.2)s,(132.3 ±45.0) s,and the error times were (0.7 ±0.3)times,( 1.4 ± 0.5 ) times,( 1.8 ± 0.9) times.Compared with the control group,latent periods of high-dose group were decreased and the error times of middle-and high-dose groups were increased significantly (P ＜ 0.05 ).Compared with the control group,the relative expression levels of NR1 and NR2A mRNA in hippocampus of middle and high-dose groups were increased significantly (P＜ 0.05 ),and the relative expression level of NR2B mRNA in highdose group was decreased significantly(P ＜ 0.05).ConclusionSub-chronic exposure to DM could increase the excitability of mice,damage the function of learning and memory,and influence the expression of NMDA receptor in hippocampus of mice.