Effects of Sublethal Doses of Thiacloprid, a Neonicotinoid Insecticide, on Learning and Memory Performance of Mice

摘要

Background and Objective: Thiacloprid (THI), a neonicotinoid insecticide, currently one of the most preferred insecticides worldwide. Although they are claimed to be less hazardous on mammals, late studies revealed the harmful effects of this kind of insecticides. However, there are few studies examining the effect of THI on learning and memory performance in the literature. This study was conducted to investigate the effects of sublethal doses of THI on learning and memory functions and to determine the effect of the protocol on biochemical parameters . Materials and Methods: In this outcome, 50, 100 and 200 mg kgsup?/supsup1/sup THI were administered by oral gavage for 3 weeks in mice (n:7). At the end of this process, a novel object recognition (NOR) and passive avoidance (PA) tests were conducted to measure learning and memory functions. Brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), glutathione peroxidase (GPx), superoxide dismutase (SOD) and catalase (CAT) levels were measured biochemically. Results: In the NOR test, reductions in the discrimination index values were observed with THI applications. The step-through latencies of the mice to enter the dark compartment in the retention trial of the PA test was reduced similarly in THI applied groups. The biochemical investigations revealed that BDNF and GPx levels in the brain tissue were significantly reduced in all groups compared to the control group, while a significant reduction in NGF levels was observed only in 200 mg kgsup?/supsup1/sup applied group. There was no significant difference in SOD and CAT levels between test groups. Conclusion: These results indicated that sublethal, chronic THI application degenerates the learning and memory functions with affecting BDNF, NGF and GPx levels.