Dendritic morphology on neurons from prefrontal cortex, hippocampus, and nucleus accumbens is altered in adult male mice exposed to repeated low dose of malathion

Abstract

Malathion is a highly neurotoxic pesticide widely used in daily life. Acute and chronic toxicity from this organophosphorus compound may cause damage to health, especially to the central nervous system. In the present work, we show the effects of chronic exposure of malathion on dendritic morphology of neurons from prefrontal cortex (PFC), hippocampus, and nucleus accumbens (NAcc) in adult male mice. Animals were injected i.p. with low dose of malathion (40 mg/kg body weight) for 14 days. Control animals were injected with corn oil, used as vehicle. Fourteen days after the last injection, brains were removed and processed by the Golgi-Cox stain method, and coronal sections were obtained to perform Sholl analysis on pyramidal neurons from the PFC, CA1 area from the hippocampus, and medium spiny cells from the NAcc. Dendritic morphology analysis included the total dendritic length, the maximum branching order, and the dendritic spine density. Results indicated a significant decrement on dendritic morphology in neurons from the hippocampus and the PFC in animals injected with malathion, whereas medium spiny neurons from NAcc showed a significant decrement only on the dendritic spine density in malathion injected mice, as compared to control mice. These results suggest that chronic toxicity of malathion alters the dendritic morphology in adult age, which may affect behavior.

The effect of consequent exposure of stress and dermal application of low doses of chlorpyrifos on the expression of glial fibrillary acidic protein in the hippocampus of adult mice

“…Dendritic morphology was assessed in the prefrontal cortex, CA1 area of the hippocampus and the nucleus accumbens following repeated (14 days) low dose intraperitoneal application of OP malathion (40 mg/kg BW) in mice. Dendritic length in the hippocampus and prefrontal cortex, and density of dendritic spines in all the three areas assessed were reduced [25]. As part of the trisynaptic circuit, afferent inputs to the hippocampus are first sent to the dentate gyrus, which then projects to the CA3 area.…”

Wip1 phosphatase positively modulates dendritic spine morphology and memory processes through the p38MAPK signaling pathway

“…Measurements were made out to a maximum of 200 mm from the soma and 20-30 mm dendritic segments were analyzed (n = 18-27 neurons for each studied genotype) and protrusions were measured as described previously. 59 No distinction was made between the different spine types. The analysis of dendritic morphology was performed using Zeiss LSM Image Browser software (Version 4.2) by research assistants who were blind to genotypes and experimental manipulations.…”

Activation of Dopamine D1 Receptors Regulates Dendritic Morphogenesis Through Rac1 and RhoA in Prefrontal Cortex Neurons

“…This process may play a critical role in producing the effects of DA-releasing stimulants, such as cocaine, on addiction-related neuroadaptation [17, 18]. The main targets of DA terminals in the PFC are pyramidal neurons, and the D1 receptor plays a particularly important role in mediating pyramidal cell morphogenesis after cocaine treatment [14, 19]. Importantly, recent studies have reported that repeated treatment of neurons with DA in vitro may model the effects of repeated cocaine use in vivo [20].…”