Neurotoxic effects of different sizes of plastics (nano, micro, and macro) on juvenile common carp (Cyprinus carpio)

Abstract

Using common carp as a model, we assessed the effects of polyethylene (PE) plastics on the brain. We measured activity of acetylcholinesterase (AChE), monoamine oxidase (MAO), and the content of nitric oxide (NO) in carp brain following exposure to 100 mg/L of either macroplastics (MaP), microplastics (MPs), or nanoplastic (NPs) for 15 days compared to an unexposed group. Following exposure, each biochemical biomarker was reduced 30–40%, with a higher magnitude of change corresponding to the smaller size of the particles (NPs > MPs > MaPs). In the carp tectum, exposure for 15 days to plastic particles caused varying degrees of necrosis, fibrosis, changes in blood capillaries, tissue detachment, edema, degenerated connective tissues, and necrosis in large cerebellar neurons and ganglion cells. In the carp retina, there was evidence for necrosis, degeneration, vacuolation, and curvature in the inner layer. Here we provide evidence that exposure to plastic particles can be associated with neurotoxicity in common carp.

Direct Quantification of Nanoplastics Neurotoxicity by Single‐Vesicle Electrochemistry

“…Though calling for further investigations, the sulfonated PS nanoplastics could adsorb catecholamine molecules through electrostatic attraction and conjugated interactions, resulting in fewer diffusional neurotransmitters detectable by the nanoelectrode. Besides, PS nanoplastics may down‐regulate tyrosine hydroxylase (TH) of catecholamine synthesis at the genomic level, or directly interact with vesicular proteins like vesicular monoamine transporter (VMAT) to impair cytosolic catecholamine transport into vesicles [34–36] …”

“…Besides, PS nanoplastics may down-regulate tyrosine hydroxylase (TH) of catecholamine synthesis at the genomic level, or directly interact with vesicular proteins like vesicular monoamine transporter (VMAT) to impair cytosolic catecholamine transport into vesicles. [34][35][36] We moved forward with amperometry to investigate the vesicle exocytotic activity of PS nanoplastics-exposed PC12 cells. Similar to IVIEC, this method monitors exocytotic events at ultrahigh spatiotemporal resolution and sensitivity, counts neurotransmitter molecules excreted during a single exocytotic event and interprets the vesicular release kinetics by electrochemical oxidation currents at a microelectrode.…”

Visualization of poikilocytosis as an emerging erythrocytic biomarker for fish health assessment

“…Despite advancements in medical technology, the analysis of erythrocyte morphology remains fundamental in hematological assessment, with a growing emphasis on poikilocytosis as a crucial biomarker for xenobiotic exposure and environmental quality [157,194,195]. Ongoing research is increasingly dedicated to exploring hematological changes induced by microplastics, and their contamination in aquatic environments has raised concerns in modern aquaculture [94,203]. There is a belief that these changes may be irreversible or necessitate an extended recovery period, underscoring the need for further investigation.…”

Adverse Effects of Non-Metallic Nanoparticles in the Central Nervous System

“…In line, 15 days of exposure to polyethylene nano-and microplastic caused varying degrees of necrosis, fibrosis, changes in blood capillaries, tissue detachment, edema, degenerated connective tissues, and necrosis in large cerebellar neurons and ganglion cells in the tectum of juvenile common carp (Cyprinus carpio). The changes were accompanied by a decrease in the activity of acetylcholinesterase (aChE) [168]. The gut-brain axis related toxicity of nanoplastic was recently reviewed, and it is clear that these particles may induce oxidative stress, disturb neurodevelopment, and impact behaviour and immune system activation [165].…”