Prenatal exposure on nanoplastics: A study of spatial transcriptomics in hippocampal offspring

Nanoplastics, as environmental contaminants, are thought to have irreversible impacts on the developing brains of infants and early children; however, the degree of the effects and the mechanisms of damage are unknown. In this study, spatial transcriptomics was used to investigate changes in the hippocampal region of rats descended from maternal exposure to polystyrene nanoplastics (PS-NPs), and the transcriptomes of each spot were sequenced, allowing us to visualize the hippocampus's transcriptional landscape as well as clarify the gene expression profiles of each cell type. Spatial transcriptomics was used to explore changes in the hippocampus region of rats exposed to PS-NPs during brain formation and maturation.The study's findings showed that the offspring hippocampal region had fewer neurons, more astrocytes, and more excitatory neurons 1(ExN1). The pseudo-time study of astrocytes revealed a decrease in C3-type astrocytes and an increase in C2-type astrocytes. This finding raises the possibility that memory impairment in the offspring may result from the developmental obstruction of astrocytes following the intervention of PS-NPs. Moreover, the annotations of four hippocampus regions, CA1, CA2-3, DG, and HILUS, as well as the GO and GSVA of several cell types, revealed deficiencies that can contribute to learning memory impairment. The analysis suggested that decreased neuroglutamate (Glutamate) and γ-aminobutyric acid (GABA) secretion in offspring after PS-NPs intervention was associated with depression. Lastly, intercellular communication revealed alterations in several ligand receptor pathways associated with an increase in astrocytes. In conclusion, spatial transcriptomics reveals that maternal exposure to nanoplastics influences the development of the offspring's hippocampal brain and causes neurotoxicity, which accounts for the offspring's reduction in learning memory function.