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Updated: Jun 25, 2026
Studying Neurobehavioral Effects of Environmental Pollutants on Zebrafish Larvae
Published on: February 5, 2020
Photoaging of Facial Scrub Microbeads Causes Neurobehavioral Impairment in Zebrafish Larvae through Mitochondrial
Ping Ding1, Jiayi Zhang1, Xin Li1
1Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou 510655, China.
Abstract:
Personal-care-product-derived microbeads are an important source of primary microplastics (MPs), yet their environmental transformation and toxicity remain unclear. Here, facial scrub (FS) microbeads were subjected to simulated photoaging and evaluated in zebrafish larvae at an environmentally relevant concentration. Photoaging promoted the formation of environmentally persistent free radicals (EPFRs), altered FS physicochemical properties, and enhanced the release of organic additives and heavy metals. Compared to virgin FS, photoaged FS (FS-60) induced stronger neurobehavioral impairment, including reduced tail coiling, swimming activity, and inner zone duration, mainly driven by leachates and EPFR-associated reactivity. Transcriptomic and biological analyses revealed disrupted mitochondrial function and neuronal signaling. FS-60 impaired central nervous system and motor neuron development, altered neurotransmitter levels (acetylcholine, serotonin, and γ-aminobutyric acid), and downregulated neurodevelopment-related genes. Moreover, FS-60 induced mitochondrial dysfunction, as supported by TEM-observed mitochondrial structural damage, elevated reactive oxygen species (ROS) and cytochrome c release, reduced ATP production and NAD+/NADH ratios, and suppressed electron-transport-chain-related genes. Mitoquinone mesylate (MitoQ) significantly alleviated locomotor deficits and ROS accumulation, confirming mitochondrial dysfunction as a key driver of FS-induced neurotoxicity. This study demonstrates that photoaging amplifies the neurotoxicity of cosmetic microbeads and should be considered in ecological risk assessment.
Insights
Photoaging significantly increases the neurotoxicity of cosmetic microbeads by releasing harmful substances and free radicals. This process disrupts mitochondrial function and neurodevelopment in zebrafish, highlighting risks from aged microplastics.
Area of Science:
- Environmental Science
- Toxicology
- Neuroscience
Background:
- Microplastics (MPs) from personal care products are primary pollutants.
- Environmental transformation and toxicity of cosmetic microbeads are not well understood.
Purpose of the Study:
- To investigate the impact of photoaging on facial scrub microbeads.
- To assess the neurotoxicity of virgin and photoaged microbeads in zebrafish larvae.
Main Methods:
- Simulated photoaging of facial scrub microbeads.
- Exposure of zebrafish larvae to microbeads.
- Neurobehavioral assessments (tail coiling, swimming activity).
- Transcriptomic analysis, mitochondrial function assays, and neurotransmitter level measurements.
Main Results:
- Photoaging generated persistent free radicals, altered microbead properties, and increased leachate release.
- Photoaged microbeads caused significant neurobehavioral impairment and neurodevelopmental issues in zebrafish.
- Mitochondrial dysfunction, oxidative stress, and disrupted neuronal signaling were key mechanisms.
Conclusions:
- Photoaging amplifies the neurotoxicity of cosmetic microbeads.
- Mitochondrial dysfunction is a critical factor in microplastic-induced neurotoxicity.
- Ecological risk assessments must consider the aged state of microplastics.
