Exposure to polystyrene microplastics impairs hippocampus-dependent learning and memory in mice
Chiang‐Wen Lee, Lee‐Fen Hsu, I.-Lin Wu, Yung‐Li Wang, Wei-Chen Chen, Yanjun Liu, Lu-Tang Yang, Chong-Lun Tan, Yueh-Hsia Luo, Chia-Ching Wang, Hui‐Wen Chiu, Thomas C.‐K. Yang, Yen‐Yue Lin, Hsin‐An Chang, Yao‐Chang Chiang, Ching-Hsiang Chen, Ming‐Hsueh Lee, Kuo‐Ti Peng, Cathy Chia‐Yu Huang
Abstract
Microplastics (MPs) pollution has become a serious environmental issue worldwide, but its potential effects on health remain unknown. The administration of polystyrene MPs (PS-MPs) to mice for eight weeks impaired learning and memory behavior. PS-MPs were detected in the brain especially in the hippocampus of these mice. Concurrently, the hippocampus had decreased levels of immediate-early genes, aberrantly enhanced synaptic glutamate AMPA receptors, and elevated neuroinflammation, all of which are critical for synaptic plasticity and memory. Interestingly, ablation of the vagus nerve, a modulator of the gut-brain axis, improved the memory function of PS-MPs mice. These results indicate that exposure to PS-MPs in mice alters the expression of neuronal activity-dependent genes and synaptic proteins, and increases neuroinflammation in the hippocampus, subsequently causing behavioral changes through the vagus nerve-dependent pathway. Our findings shed light on the adverse impacts of PS-MPs on the brain and hippocampal learning and memory.