Table 3 Summary of the animal studies on the association between PM and cognitive decline
From: The pathogenic effects of particulate matter on neurodegeneration: a review
Type of PM | Exposure duration | Species | Gender | Genotype | Age | Tests | Cognitive function | Cognitive impaired or not | References |
|---|---|---|---|---|---|---|---|---|---|
Cognition | |||||||||
 PM2.5 | 150 days | Wistar rats | Male | Wild type | 45 days old | The spontaneous nonmatching-to-sample recognition test | Discriminative memory and habituation | Impaired | [51] |
 PM2.5 | 10 months | C57BL/6 mice | Male | Wild type | 4-week-old | Barnes maze | Learning and memory | Impaired | [52] |
 UFPM | 2 weeks | Mice | Male | 3 × TgAD mice | 12.5- month-old | Radial arm maze; Novel object recognition test | Spatial memory; Short-term memory | Impaired | [53] |
PM2.5 | 3, 6, 12-months Intratracheally injection of 20 mg/kg PM2.5 every 7 days | Sprague–Dawley rats | Male | Wildtype | 2-month-old | Morris water maze test; Tail flick and hot plate test | Spatial learning and memory; Sensory function | Impaired | [103] |
 PM2.5 | 3 months | Mice | Female | 3 × TgAD mice | 6- month-old | Morris water maze | Learning and memory | Not impaired | [54] |
Type of PM | Exposure duration | Species | Gender | Genotype | Age | Abnormality | Potential regulating signals | Treatment | References |
|---|---|---|---|---|---|---|---|---|---|
Neurodegenerative-like pathology | Â | ||||||||
 Artificial PM | 4.5 months | Wistar rats | – | Wild type |  ~ 5 weeks of age | Neuronal loss: pure cortical neuronal loss, selective neuronal loss, nuclear pyknosis, karyolysis, and karyorrhexis | – | – | [59] |
 UFPM | 8 days | C57BL6/J mice | Male and female | Wild type | 8-week-old | Ventriculomegaly | – | – | [60] |
 UFPM | 2 weeks | B6/129 hybrid mice | Male | 3 × Tg AD | 12.5–14 months | Aβ deposition and neuroinflammation | – | – | [62] |
 PM2.5 | 9 months | C57BL/6 mice | Male | Wild type | 8-week-old | Increased Aβ1-40 | BACE/APP/Aβ | – | [63] |
 PM2.5 | 4 weeks | C57BL/6 mice | Male | Wild type | 8-week-old | Cognitive impairment Synaptic dysfunction Neuroinflammation | NF-κB/miR-574-5p/BACE1 | miR-574-5p or BACE1 knockdown | [64] |
Oxidative stress | |||||||||
 UFPM/PM2.5 | 3 weeks/60 min | C57BL6 mice/Wistar rats | Male | Wild type | 11–12 months old/90 days old | Oxidative stress in hippocampus | redox homeostasis | – | artificial UFPM (no oxidant): [74]; PM2.5: [75] |
 UFPM | 8 weeks | Sprague–Dawley rats | Male | Wild type | 6-week-old | Oxidative stress, neuroinflammation, and ER stress in the striatum | Nrf2/HO-1 signaling; NF-κB signaling; XBP-1/Bip | – | [76] |
 PM2.5 | 28 days | C57BL/6 mice | Male | Nrf2−/− | – | Severe neuronal injury in the olfactory bulb | Nrf2 | Nrf2-mediated defenses against oxidative stress | [78] |
Neuroinflammation | |||||||||
 Concentrated ambient PM | 6 weeks | C57BL/6J mice | Male | ApoE−/− | 6-week-old | Neuroinflammation | MAP kinase signaling pathways | – | [86] |
 Nanosized PM (diameter < 0.2 μm) | 10 weeks | C57BL/6J mice | Female | Wild type | 3-month-old | Brain inflammatory responses | TLR4 | – | [88] |
 Nanosized PM (diameter < 0.2 μm) | 10 weeks | C57BL/6J mice | Male | Wild type | 15–16 weeks | Increased complement C5/C5α protein and CD88; Activated microglia in the corpus callosum | C5/C5α complement pathway | – | [91] |
BBB & NVU injury | |||||||||
 Mixed vehicle exhaust | 30 days | C57BL/6 mice | Male | ApoE−/− | 12-week-old | BBB permeability increase; Decreased tight junction proteins | – | – | [95] |
 PM and ozone mixture | 4 h | Fischer-344 rats | Male | Wild type | – | Dysregulation of vasoregulatory pathways (ET-1 & iNOS mRNA expression) | – | – | [100] |