Exposure to polystyrene microplastics impairs hippocampus-dependent learning and memory in mice

J Hazard Mater. 2022 May 15;430:128431. doi: 10.1016/j.jhazmat.2022.128431. Epub 2022 Feb 4.


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.

Keywords: Brain; Learning and memory; Polystyrene microplastics.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Glutamic Acid
  • Hippocampus
  • Mice
  • Microplastics*
  • Plastics
  • Polystyrenes* / toxicity


  • Microplastics
  • Plastics
  • Polystyrenes
  • Glutamic Acid