Effects of micro- and nanoplastic exposure during critical developmental periods on the central nervous system: A systematic review of rodent models.
Level 5 - mechanism / opinion, no new human data
Systematic review of preclinical animal (rodent) studies
PubMed 42604711 · doi:10.1016/j.neuro.2026.103543
What was done
Researchers conducted a systematic review according to PRISMA guidelines (PROSPERO CRD420251127469) across MEDLINE, EMBASE, Scopus, and Web of Science through August 18, 2025. They identified in vivo mammalian studies assessing micro- and nanoplastic (MNP) exposure (polystyrene, polypropylene, polyethylene, or polyvinyl chloride; primarily oral administration) during gestation, lactation, childhood, or adolescence compared to unexposed or vehicle controls. Study reliability was assessed using ToxRTool, and findings from 20 rodent studies (rats and mice) were narratively synthesized across developmental exposure windows.
What was found
The abstract reports narrative findings without providing specific quantitative effect sizes or numerical values. Across exposure windows, MNP exposure in rodents was consistently associated with oxidative stress, mitochondrial dysfunction, neuroinflammation (microglial and astrocytic activation), apoptosis, ferroptosis, impaired neurogenesis, abnormal myelination, and synaptic or dendritic disruptions. Neurochemically, studies reported GABAergic and glutamatergic imbalances along with dopaminergic changes. Behaviorally, exposed rodents exhibited learning and memory deficits, increased anxiety-like behavior, altered sociability, and repetitive or stereotyped behaviors, alongside gut-microbiota-brain axis disruption.
Why it matters
The review maps emerging biological pathways through which ingested or inhaled micro- and nanoplastics could disrupt neurodevelopment in mammalian systems, establishing a mechanistic foundation for environmental health risk assessments.
Limits
All findings are derived from rodent models, limiting direct generalizability to human neurodevelopment. The abstract reports no quantitative meta-analytic pooling, effect sizes, exposure thresholds, or particle concentrations. High heterogeneity among plastic polymer types, particle sizes, and exposure schedules prevented quantitative synthesis, and the abstract notes an absence of standardized, environmentally relevant exposure doses, longitudinal follow-up, and sex-stratified analysis.
Cited by
- supports Nanoplastics smaller than 1 micrometer can cross the blood-brain barrier.