Effects of Early Life Exposure to the Insecticide Cyfluthrin on Cognitive Dysfunction in Offspring of Rats:...

The present investigation was designed to assess how perinatal contact with the pyrethroid insecticide cyfluthrin (CY) influences cognitive performance in developing rat progeny and to clarify the contributing cellular events through examination of neuroinflammatory processes alongside pyroptotic and apoptotic pathways. An experimental framework involving CY administration during gestation was implemented using Sprague-Dawley (SD) dams, with subsequent monitoring of placental parameters and neonatal outcomes. Once offspring reached postnatal day twenty-one, their behavior was characterized via a battery consisting of the open field paradigm, novel object recognition task, and the Morris water navigation test. Hippocampal tissue architecture and fine structural details were visualized by employing hematoxylin-eosin (HE) staining and Nissl substance labeling. Protein and transcript abundances for pro-inflammatory mediators (TNF-α, IL-6), synaptic constituents (postsynaptic density protein-95, PSD-95; synaptophysin, SYP), and pyroptotic machinery components (NLRP3, GSDMD, Caspase-1) within hippocampal homogenates were quantified through immunoblotting and real-time quantitative PCR procedures, and the spatial distribution of these molecules was validated via immunohistochemical detection. Neuronal apoptosis was assessed by TUNEL staining. The results demonstrated that gestational CY exposure led to reduced placental weight and diameter, decreased blood sinus area in the labyrinth zone, lower offspring birth weight, and impaired catch-up growth. Behavioral tests revealed that CY-exposed offspring exhibited diminished spontaneous locomotor activity, impaired novel object recognition memory, and significant deficits in spatial learning and memory. Pathological analysis showed disorganized neuronal arrangement and reduced Nissl bodies in the hippocampal CA1 region. Compared to the control group, CY exposure markedly upregulated the protein expression of TNF-α and IL-6, downregulated PSD-95 and SYP, activated the NLRP3/GSDMD/Caspase-1-mediated pyroptotic pathway, and increased the expression of the apoptotic protein Caspase-3, culminating in a significant increase in hippocampal neuronal apoptosis. In conclusion, early-life exposure to cyfluthrin impairs cognitive function in offspring, an effect closely associated with the induction of hippocampal neuroinflammation and the activation of pyroptotic and apoptotic pathways. These findings provide novel toxicological evidence for a more comprehensive assessment of the potential health risks posed by CY exposure in human populations.