CELL DIFFERENTIATION AND DEGENERATION IN THE SUBVENTRICULAR ZONE OF ADULT MICE FOLLOWING EXPOSURE TO FIPRONIL

Fipronil is a broad-spectrum phenylpyrazole insecticide widely used in agriculture and pest control that can cross the blood–brain barrier and accumulate in mammalian brain tissue. While its primary mechanism of action involves antagonism of gamma-aminobutyric acid receptors, evidence from rodent studies indicates that fipronil exposure can induce oxidative stress, alter neurotransmitter systems, and exert neurotoxic effects in non-target organisms. Alterations in neural cell differentiation and survival have been observed in pesticide models, suggesting that environmental toxicants like fipronil may impair adult neurogenesis, particularly in proliferative zones such as the subventricular zone (SVZ). Therefore, the objective of this study was to examine the effect of prenatal fipronil exposure on differentiation of nitrergic cells and cell degeneration in the SVZ of adult mice. Fipronil was administered to experimental mice during the preimplantation period (three oral applications) using a syringe. To assess cell differentiation in the SVZ, NADPH-diaphorase histochemistry was employed. Fluoro-Jade C fluorescent staining was used to evaluate cell degeneration in the SVZ of mice after fipronil exposure. Our findings show that fipronil exposure significantly enhances the differentiation of nitrergic cells within the SVZ, a region critical for ongoing neuronal replacement and olfactory bulb integration. On the other hand, no significant changes in cell degeneration were found after fipronil exposure. These findings underscore the need for further investigation into the effects of fipronil on SVZ neurogenic dynamics and the potential long-term consequences for brain function.
Supported by the grants APVV-23-0274 a VEGA 2/0101/25