Imidacloprid Impacts on Neurobehavioral Performance, Oxidative Stress, and Apoptotic Events in the Brain of Adolescent and Adult Rats

Abstract

Currently, imidacloprid (IMI) is the first insecticide and the second agrochemical highly applied all over the world. Here, we report on the impacts of IMI on neurobehavioral performance, oxidative stress, and apoptotic changes in the brain in either adult or adolescent rats. Forty male rats (adult and adolescent) were allocated to four groups. IMI groups were orally given 1 mg IMI/kg b.wt. dissolved in corn oil, whereas the controls were orally administered corn oil daily for 60 days. The obtained results demonstrated that IMI exposure resulted in less exploratory activity, deficit sensorimotor functions, and high depression. Levels of neurotransmitter including serotonin, gamma-aminobutyric acid, and dopamine were significantly reduced. Oxidative damage of brain tissues was evident following IMI exposure represented by the high levels of protein carbonyl, 8-hydroxyguanosine, and malondialdehyde, but total antioxidant capacity was reduced. Histopathological investigations of the brain tissues of IMI treated group revealed varying degrees of degeneration of the neuron. The immunohistochemical evaluation revealed a strong presence of glial fibrillary acidic protein (GFAP) and Bax positive cells, but a low expression of Bcl-2. These injurious impacts of IMI were very prominent in the adult rats than in the adolescent rats. Conclusively, exposure to IMI even at very low concentration could induce multiple neurobehavioral aberrations and neurotoxic impacts, especially in adults.

Modulatory Effect of Ginger Aqueous Extract against Imidacloprid-Induced Neurotoxicity in Rats

“…The results of GABA showed that IMI exposure caused a significant decrease in GABA level. These results agree with that obtained by Abd-Elhakim et al [28]. Administration of GAE simultaneously with IMI modifies the release of some neurotransmitters particularly GABA [29].…”

Combined exposure to dinotefuran and chronic mild stress counteracts the change of the emotional and monoaminergic neuronal activity induced by either exposure singly despite corticosterone elevation in mice

“…On the other hand, some reports of NNs show the different results from the present study. TMX has been shown to significantly inhibit locomotor activity [30], CTD was shown to significantly increase anxiety-like behavior [17] and the levels of 5-HT, GABA and DA have been shown to be significantly reduced by IMI administration [1]. The effects on locomotor activities, the anxiety-like behaviors and the neurotransmitters of mice were observed to vary according to the type of NNs.…”

Establishment of a Highly Sensitive Analytical Method For Measurement of Monoamine Neurotransmitters Using Mass Spectrometry

“…Yoneda et al 6 also reported that long-term administration of dinotefuran to mice caused a dose-dependent increase in spontaneous locomotor activity. Chronic administration of IMI has been reported to cause a decrease in voluntary locomotion, an increase in resting time, and depression 3,8,9 ; since monoamines regulate brain functions such as behavior, memory, emotion, and learning, monoamine disruption may be involved in the development of those symptoms.…”

“…Their toxicity to mammals has been reported in recent years, including neurotoxicity, reproductive toxicity, and hepatotoxicity when administered to mice and rats 9,10,11−19 . There have been many reports of neurotoxicity, including increased anxiety-like behavior and changes in spontaneous locomotion [3][4][5][6][7][8][9] . In particular, Hirano et al 5 found that clothianidin (CLO), an NN, increased anxiety-like behavior even at concentrations below the no observed adverse effect level (NOAEL).…”