# Effects of Short-Term Exposure to Polystyrene Nanoplastics on the Nervous System: Calcium Homeostasis, BDNF and Synaptic Plasticity

## TL;DR

This study explores how short-term exposure to polystyrene nanoplastics affects the nervous system, particularly through changes in calcium signaling and brain-derived neurotrophic factor.

## Contribution

The study reveals a novel mechanism by which nanoplastics may impair synaptic plasticity via calcium signaling and BDNF modulation.

## Key findings

- PS-NPs interfere with calcium ion signaling and reduce CaMKIIα activity.
- PS-NPs downregulate CREB expression and modulate BDNF levels, impacting synaptic plasticity.

## Abstract

(1) Background: The increasing environmental concentration of polystyrene nanoplastics (PS-NPs) may pose a risk of human exposure and health threats. Previous studies have demonstrated that exposure to PS-NPs poses a threat to neural synaptic plasticity, yet the underlying mechanisms remain unclear. (2) Methods: Hippocampal astrocytes and neurons were co-cultured, exposed to PS-NPs at concentrations of 10, 50, and 100 μg/mL, and cytotoxicity was assessed. We investigated PS-NPs-induced impairment of synaptic plasticity by regulating the brain-derived neurotrophic factor (BDNF). (3) Results: Calmodulin-dependent protein kinase II (CaMKII) is a central molecular organizer of synaptic plasticity, learning, and memory, and its activity is intrinsically linked to intracellular calcium ion concentration. Our research indicates that PS-NPs may interfere with calcium ion signaling and CaMKIIα activity, thereby reducing CaMKIIα activity. This subsequently downregulates the expression of cAMP response element-binding protein (CREB), modulates BDNF expression, and impacts synaptic plasticity. (4) Conclusions: In summary, this study primarily focused on the effects of PS-NPs exposure on hippocampal synaptic plasticity.