Table 2.
Final Included Articles from Literature Search 2: Air Pollution and Frontolimbic Brain Regions
| First author & year | Species | Pollutant | Exposure Window | Duration of Exposure | N | Gender or sex | Exposure Assessment Method | Period of Behavioral Assessment | Brain regions assessed | Brain outcome assessed |
|---|---|---|---|---|---|---|---|---|---|---|
| Avila-Costa et al. (1999) | Rats (Wistar) | Ozone | Not reported | 4 hours | 24 | Male | Whole Body Inhalation | Not reported | Hippocampus | Dendritic spine length or neurite changes |
| Avila-Costa et al. (2001) | Rats (Wistar) | Ozone | Not reported | 4 hours | 24 | Male | Whole Body Inhalation | Not reported | Prefrontal Cortex | Dendritic spine length or neurite changes |
| Dorado-Martínez et al. (2001) | Rats (Wistar) | Ozone | Not reported | 4 hours | 136 | Male | Whole Body Inhalation | Not reported | Hippocampus, Frontal Cortex | Lipid peroxidation |
| Niño-Cabrera (2002) | Rats (Wistar) | Ozone | Late-life | 4 hours | 7 (3 controls) | Male | Whole Body Inhalation | Late--ife | Hippocampus CA1 and Prefrontal Cortex | Necrotic processes, myelin alterations, altered astrocytes |
| Calderon-Garciduenas et al. (2003) | Dogs | Multiple pollutants | Lifetime | Dogs - 1 year, Humans - 2–10 years | 40 (14 controls) | Both | Whole Body Inhalation | Adulthood | Hippocampus, Frontal Cortex | Altered DNA, amyloid, immune reactions, inflammatory reactions, altered astrocytes |
| Calderon-Garciduenas et al. (2004) | Humans | Multiple pollutants | Lifetime | 34–83 years | 19 (9 low pollution, 10 high pollution) | Both | Lived in polluted city versus unpolluted city | Adulthood & Late-life | Hippocampus, Frontal Cortex | Altered DNA, amyloid, inflammatory reactions |
| Santucci et al. (2006) | Mice (CD-1) | Ozone | Prenatal | 47 days | 8 (4 females, 4 males) | Both | Whole Body Inhalation | Adulthood | Hippocampus | Neurotrophins |
| Calderon-Garciduenas et al. (2008) | Humans, Dogs | Multiple pollutants | Lifetime | Humans - 9.2 + 2.3 years, Dogs - 12–19 months | 73 children (55 high polluted, 18 low polluted), 12 dogs (7 high polluted, 5 low polluted) | Both | Lived in polluted city versus unpolluted city | Childhood | Subcortical prefrontal white matter | White matter lesions, inflammatory reactions |
| Gerlofs-Nijland et al. (2010) | Rats (Fischer F344/DUCRL) | Multiple pollutants | Adulthood | 4 weeks | 15/group | Male | Combination of whole body inhalation and nose-only inhalation | Adulthood | Hippocampus | No effects observed (inflammatory reactions, immune reactions) |
| Rivas-Arancibia et al. (2010) | Rats (Wistar) | Ozone | Not reported | 15–90 days | 110 (22 in each group) | Male | Whole Body Inhalation | Not reported | Hippocampus | Microglia, altered neurogenesis, altered cell proliferation, lipid peroxidation, altered astrocytes, |
| Suzuki et al. (2010) | Mice (ICR) | DEP | Prenatal | 2 weeks | 272 (114 exposed, 161 control) | Male | Whole Body Inhalation | Childhood | Prefrontal Cortex, Hippocampus | Neurotransmitter or neuromodulator metabolites and receptors |
| Calderon-Garciduenas et al. (2011) | Humans | Multiple pollutants | Lifetime | 7.1 + 0.69 years | 30 (10 low polluted, 20 high polluted) | Both | Lived in polluted city versus unpolluted city | Childhood | Prefrontal white matter, temporal white matter, hippocampus, amygdala | Brain volumes, white matter lesions |
| Fonken et al. (2011) | Mice (C57BL/6) | PM2.5 | Childhood through Adulthood | 10 months | Not reported | Male | Whole Body Inhalation | Adulthood | Hippocampus | Dendritic spine length or neurite changes, inflammatory reactions |
| Gackiere et al. (2011) | Rats (Wistar) | Ozone | Adolescence | Up to 120 hours | Not reported | Male | Whole Body Inhalation | Adolescence | Amygdala | Activated neurons |
| Morgan et al. (2011) | Mice (C57BL/6J) and Rats (F344) | nPM | Adulthood | 10 weeks | Not reported | Male | Whole Body Inhalation | Adulthood | Hippocampus | Microglia, neurotransmitter or neuromodulator metabolites and receptors, dendritic spine length or neurite changes, altered astrocytes, inflammatory reactions |
| Bos et al. (2012) | Mice (C57BL6) | PM2.5 | Adolescence | 5 days | 20 | Male | Whole Body Inhalation | Adulthood | Hippocampus | Inflammatory reactions, immune reactions |
| Hallberg et al. (2012) | Rats (Wistar Han) and Mice (C57BL/6) | DEP | Not reported | 6 hours | 5/group | Both | Whole Body Inhalation | Not reported | Hippocampus | No effects observed (inflammatory reactions) |
| Davis et al. (2013) | Mice (C57BL/6J) | nPM | Prenatal | 10 weeks | 4/group | Both | Whole Body Inhalation | Early-life | Hippocampus | Necrotic processes |
| Guerra et al. (2013) | Rats (Sprague-Dawley) | Multiple pollutants | Adolescence through Adulthood | 8 weeks | Not reported | Male | Whole Body Inhalation | Adulthood | Frontal cortex, Hippocampus | Mitochondrial changes, misfolded proteins, inflammatory reactions |
| Rodriguez-Martinez et al. (2013) | Rats (Wistar) | Ozone | Not reported | Up to 60 days | 180 (36/group) | Male | Whole Body Inhalation | Not reported | Hippocampus | Oxidative stress markers, swollen and damaged cells, mitochondrial changes |
| Win-Shwe et al. (2013) | Mice (BALB/c) | Multiple pollutants | Adulthood | 1 single intranasal instillation dose of 50 ul | 24, 8/group | Male | Intranasal instillation | Adulthood | Hippocampus | Inflammatory reactions |
| Gomez-Crisostomo et al. (2014) | Rats (Wistar) | Ozone | Not reported | Up to 90 days | 72 | Male | Whole Body Inhalation | Not reported | Hippocampus | Necrotic processes, altered cell proliferation, oxidative stress markers |
| Kinawy et al. (2014) | Rats (Wister) | DEP | Not reported | Single session - 30 mins, Chronic session - 8 weeks | 90, 30/group | Male | Whole Body Inhalation | Not reported | Hippocampus | Neurotransmitter or neuromodulator metabolites and receptors |
| F. Wang et al. (2014) | Mice (Kun Ming) | VOCs | Childhood through Adulthood | 3 months | 60 | Male | Whole Body Inhalation | Adulthood | Hippocampus | Decreased number of neurons, altered cell proliferation, oxidative stress markers, lipid peroxidation, neurotransmitter or neuromodulator metabolites and receptors |
| Win-Shwe et al. (2014) | Mice (BALB/c) | DEP | Childhood through Adulthood | 1–3 months | 6/group | Both | Whole Body Inhalation | Adulthood | Hippocampus | Neurotransmitter or neuromodulator metabolites and receptors |
| Calderon-Garciduenas et al. (2015) | Humans | Multiple pollutants | Lifetime | Children - 12.45 + 3.4 years. Adults - 37.5 + 6.77 | 57 polluted children and 9 control children. 48 polluted adults, and 7 control adults. | Both | Lived in polluted city versus unpolluted city | Childhood and Adolescence, Adulthood | Hippocampus | MR Spectroscopy |
| Heidari Nejad et al. (2015) | Mice (BALB/c) | DEP | Adulthood | 8 days | 12/group | Both | Whole Body Inhalation | Adulthood | Hippocampus | Altered astrocytes, blood brain barrier integrity |
| Hallberg et al. (2015) | Rats (Wistar Han) | DEP | Not reported | Up to 24 months | 10, 5/group | Both | Not reported | Not reported | Hippocampus | No effects observed (oxidative stress makers) |
| Hernandez-Zimbron and Rivas-Arancibia (2015) | Rats (Wistar) | Ozone | Not reported | Up to 90 days | 72, 12/group | Male | Whole Body Inhalation | Not reported | Hippocampus | Amyloid, mitochondrial changes |
| Kodavanti et al. (2015) | Rats (Long-Evans) | VOCs | Adulthood | Acute - 6 hours, Subchronic - 13 weeks | Not reported | Male | Whole Body Inhalation | Adulthood | Frontal Cortex, Hippocampus | Oxidative stress markers |
| Peterson et al. (2015) | Humans | PAH | Prenatal, Childhood | Prenatal - 48 hours, Postnatal 5 years | 40 | Both | Combination of personal air monitoring, and urinary metabolites | Childhood | Frontal lobe white matter, Temporal lobe white matter, dorsal prefrontal white matter | Brain volumes |
| Yao et al. (2015) | Rats (Wistar) | SO2 | Not reported | 90 days | 20/group | Male | Whole Body Inhalation | Adulthood | Hippocampus | Neurotransmitter or neuromodulator metabolites and receptors, inflammatory reactions, memory related kinases and genes |
| Calderon-Garciduenas et al. (2016) | Humans and Dogs | Multiple pollutants | Lifetime | Dogs - 3.11 + 0.67 years, Humans - 12.67 + 4.9 years | 9 high polluted dogs, 6 control dogs | Both | Lived in polluted city versus unpolluted city | Not reported | Frontal white and gray matter in dogs. Prefrontal white and gray matter in children | Cerebrovascular changes |
| Cole et al. (2016) | Mice (C57BL/6) | DEP | Adulthood | 6 hours | 3–6/group | Both | Whole Body Inhalation | Adulthood | Hippocampus | Inflammatory reactions, microglia, lipid peroxidation |
| Hernandez-Zimbron and Rivas-Arancibia (2016) | Rats (Wistar) | Ozone | Not reported | Up to 90 days | 72 (12/group) | Male | Whole Body Inhalation | Not reported | Hippocampus | Endoplasmic reticulum changes, amyloid |
| Rodriguez-Martinez et al. (2016) | Rats (Wistar) | Ozone | Not reported | Up to 90 days | 108 | Male | Whole Body Inhalation | Not reported | Hippocampus | Endoplasmic reticulum changes, necrotic processes |
| Yokota, Oshio, Moriya, et al. (2016) | Mice (ICR) | DEP | Prenatal | 2 weeks | 15/group | Male | Whole Body Inhalation | Adulthood | Prefrontal cortex, amygdala | Neurotransmitter or neuromodulator metabolites and receptors |
| Chao et al. (2017) | Rats (Sprague-Dawley) | PM2.5 | Prenatal | Up to 25 mg instillation intratracheal test | 12 | Not reported | Intratracheal instillation | Not reported | Hippocampus | Memory related kinases and genes, endoplasmic reticulum changes, altered cell proliferation |
| J. C. Chen et al. (2017) | Humans | Multiple pollutants | Adulthood, Late-life | 9 years | 1403 | Female | Bayesian maximum entropy | Late-life | Hippocampus, Frontal and Temporal Gray and White Matter | Brain volumes |
| Cheng et al. (2017) | Rats (Sprague-Dawley) | PM2.5 | Adulthood | 28 days | 20, 10/group | Male | Whole Body Inhalation | Adulthood | Hippocampus | Dendritic spine length or neurite changes |
| Ku et al. (2017) | Mice (C57BL/6) | PM2.5 | Adulthood | 4 weeks | Not reported | Male | Oropharyngeal aspiration | Adulthood | Hippocampus | Amyloid, neurotransmitter or neuromodulator metabolites and receptors, synaptic changes, altered cell proliferation |
| Nway et al. (2017) | Mice (C3H/HeN) | DEP | Prenatal and Early-life | 5 days | 8/group | Both | Whole Body Inhalation | Early-life | Hippocampus | Neurotransmitter or neuromodulator metabolites and receptors, inflammatory reactions, microglia |
| Rivas-Arancibia et al. (2017) | Rats (Wistar) | Ozone | Not reported | Up to 90 days | 72, 12/group | Male | Whole Body Inhalation | Not reported | Hippocampus | Amyloid |
| Woodward, Levine, et al. (2017) | Mice (C57BL/6J) | nPM | Adulthood | 10 weeks | Not reported | Female | Whole Body Inhalation | Adulthood | Hippocampus | Inflammatory reactions, immune reactions |
| Woodward, Pakbin, et al. (2017) | Mice (C67BL/6J) | nPM | Adulthood through Late-life | 10 weeks | 9/group | Female | Whole Body Inhalation | Adulthood and Late-life | Hippocampus | Microglia, dendritic spine length or neurite changes, neurotransmitter or neuromodulator metabolites and receptors, inflammatory reactions, myelin alterations |
| Yang et al. (2017) | Rats (Wistar) | Multiple pollutants | Not reported | 10 days | 6/group | Male | Intratracheal instillation | Not reported | Hippocampus | Inflammatory reactions, amyloid |
| Andrade-Oliva et al. (2018) | Rats (Sprague Dawley) | PM2.5 | Adulthood | Acute - 3 days, Subchronic - 8 weeks | Not reported | Male | Whole Body Inhalation | Not reported | Prefrontal Cortex | No effects observed (Neurotransmitter or neuromodulator metabolites and receptors, altered astrocytes |
| Jia et al. (2018) | Mice (C57BL/6J) | PM2.5 | Adulthood | 20 weeks | 10/group | Male | Whole Body Inhalation | Adulthood | Hippocampus | Dendritic spine length or neurite changes, inflammatory reactions, glucocorticoid receptors, |
| Kim et al. (2018) | Mice (BALB/c) | DEP | Adolescence through Adulthood | 4 weeks, 8 weeks | 32, 8/group | Female | Whole Body Inhalation | Adulthood | Prefrontal Cortex, Temporal Cortex | Synaptic changes, neurotrophins, oxidative stress markers |
| Li et al. (2018) | Rats (Sprague-Dawley) | PM2.5 | Early-life | 2 weeks | Not reported | Male | Intranasal instillation | Early-life | Hippocampus, Prefrontal Cortex | Inflammatory reactions, autism genes expression, altered astrocytes, microglia |
| Liu et al. (2018) | Mice (C57BL/6) | Multiple pollutants | Adulthood through Late-life | Up to 12 weeks | Not reported | Male | Whole Body Inhalation | Not reported | Hippocampus | Neurotrophins, necrotic processes, dendritic spine length or neurite changes, inflammatory reactions |
| Ning et al. (2018) | Mice (C57BL/6) | PM2.5 | Childhood through Adolescence | 4 weeks | Not reported | Not reported | Oropharyngeal aspiration | Not reported | Hippocampus | Energy metabolites, cholesterol metabolites, arachidonic acid metabolites, inositol phosphate metabolites, aspartic acid metabolites |
| Shih et al. (2018) | Rats (Sprague Dawley) | TRAP | Adulthood | 3 months, 6 months | 9/group | Male | Whole Body Inhalation | Adulthood | Hippocampus | Dendritic spine length or neurite changes, inflammatory reactions, brain volumes, arachidonic acid metabolites, necrotic processes |
| Valand et al. (2018) | Rats (Fisher344) | DEP | Not reported | 28 days | 7/group | Male | Whole Body Inhalation | Not reported | Hippocampus, Frontal Cortex | Genes involved in bronchial smooth muscle cells, genes associated with neuronal development, alterations in neuronal migration, swollen and damaged cells, synaptic changes, immune reactions, oxidative stress markers, dendritic spine length or neurite changes, inflammatory reactions |
| F. Wang, Z. Fangfang, et al. (2018) | Mice (Kunming) | VOCs | Childhood | 10 days | 10/group | Male | Whole Body Inhalation | Adolescence | Hippocampus | Dendritic spine length or neurite changes, neurotransmitter or neuromodulator metabolites and receptors, oxidative stress markers |
| Woodward et al. (2018) | Rats (Sprague-Dawley) | TRAP | Prenatal through Adulthood | 28 weeks | Not reported | Male | Whole Body Inhalation | Adulthood | Hippocampus | Cerebral microbleeds, altered neurogenesis, blood brain barrier integrity, microglia |
| Zheng et al. (2018) | Mice (Kunming) | PM2.5 | Prenatal | 7 days | 6/group | Not reported | Tracheal drip | Early-life | Hippocampus | Activated neurons, altered neurogenesis, mitochondrial changes, synaptic changes, immune reactions, altered cell proliferation, necrotic processes, dendritic spine length or neurite changes, inflammatory reactions |
| Bai et al. (2019) | Rats (Sprague Dawley) | TRAP | Adulthood | 3 months, 6 months | Not reported | Male | Whole Body Inhalation | Adulthood | Hippocampus | Microglia |
| Bello-Medina et al. (2019) | Rats (Wistar) | Ozone | Not reported | Up to 90 days | 80, 10/group | Male | Whole Body Inhalation | Not reported | Hippocampus | Dendritic spine length or neurite changes |
| Brunst et al. (2019) | Humans | TRAP | Early-life, Childhood, Cumulative | 1 year, 12 years | 145 | Both | Land use regression models | Adolescence | Anterior Cingulate Cortex (ACC) | MR Spectroscopy |
| Chu et al. (2019) | Rats (Sprague-Dawley) and Mice (WT and Nrfs−/− (KO)) | PM2.5 | Rats - Adulthood, Mice - Adolescence through Adulthood | Rats - 12 weeks, Mice - 9 weeks | 24, 8/group | Male | Whole Body Inhalation | Adulthood | Prefrontal Cortex | Dendritic spine length or neurite changes, inflammatory reactions, heavy metal deposits, neurotrophins, altered astrocytes, necrotic processes, oxidative stress markers, neurotransmitter or neuromodulator metabolites and receptors |
| Custodio et al. (2019) | Rats (Wistar) | Ozone | Prenatal | 20 days | 18 exposed, 16 controls | Both | Whole Body Inhalation | Adulthood | Prefrontal Cortex, Hippocampus | Neurotransmitter or neuromodulator metabolites and receptors, altered cell proliferation |
| Ehsanifar, Jafari, et al. (2019) | Mice (NMRI) | DEP | Prenatal | 3 weeks | 10/group | Male | Whole Body Inhalation | Adulthood | Hippocampus | Dendritic spine length or neurite changes, inflammatory reactions, neurotransmitter or neuromodulator metabolites and receptors |
| Ehsanifar, Tameh, et al. (2019) | Mice (NMRI) | DEP | Adulthood | 12 weeks | 48, 12/group | Male | Whole Body Inhalation | Adulthood | Hippocampus | Oxidative stress markers |
| Hedges et al. (2019) | Humans | Multiple pollutants | Adulthood and Late-life | 1 year | 18,278 | Both | Land use regression models | Adulthood & Late-life | Hippocampus | Brain volumes |
| Kim et al. (2019) | Mice (BALB/c) | DEP | Adolescence into Adulthood | 4 weeks, 8 weeks | 32, 8/group | Female | Whole Body Inhalation | Adulthood | Prefrontal Cortex, Temporal Cortex | Immune reactions, synaptic changes, necrotic processes, neurotransmitter or neuromodulator metabolites and receptors, inflammatory reactions, neuronal plasticity measures, genes associated with neuronal development |
| Li et al. (2019) | Mice (C57BL/6J) | PM2.5 | Adulthood | Acute - 24 hours, Chronic - up to 4.5 months | Acute - 10, Chronic - 6 | Male | Whole Body Inhalation | Adulthood | Hippocampus | Altered DNA |
| Liu et al. (2019) | Rats (Sprague Dawley) | PM2.5 | Early-life | 12 days | 8/group | Both | Intranasal instillation | Childhood or Adulthood | Hippocampus | Neurotrophins, synaptic changes |
| Armstrong et al. (2020) | Mice (C57/BL/6) | DEP | Adulthood and Late-life | 50 days | 16/group | Male | Whole Body Inhalation | Adulthood, Late-life | Hippocampus | Cerebrovascular changes, altered cell proliferation, amyloid, oxidative stress markers |
| Calderon-Garciduenas et al. (2020) | Humans and Mice (C57BL/6J) | Multiple pollutants | Humans - not reported, adulthood for animals | Humans - 29.8 years, Mice - 7 months | Humans (5 controls, 9 exposed). Mice - 4/group | Humans - both. Mice - Female | Humans - Lived in polluted city versus unpolluted city, Mice - whole body inhalation | Humans- Adulthood Mice – Adulthood | Humans - Frontal white matter, Mice - Frontal Cortex | Tau-related pathology, heavy metal deposits, altered DNA |
| Cho et al. (2020) | Humans | Multiple pollutants | Adulthood and Late-life | 1 year, 5 years | 957 | Both | Kriging model | Adulthood, Late-life | Frontal Cortex, Temporal Cortex, Hippocampus, Amygdala | Brain volumes |
| Cole et al. (2020) | Mice (C57BL/6J) | DEP | Prenatal through Early-life | 3 weeks | Not reported | Both | Whole Body Inhalation | Early-life, Adulthood | Hippocampus | Altered neurogenesis |
| Di Domenico et al. (2020) | Mice (Balb/C) | PM2.5 | Prenatal, Childhood through Adulthood | 85 days | Not reported | Male | Whole Body Inhalation | Adulthood | Hippocampus | Neurotrophins, altered astrocytes, microglia |
| Gale et al. (2020) | Humans | Multiple pollutants | Adulthood and Late-life | 1 year, 4 years | 18,288 | Both | Land use regression models | Adulthood & Late-life | Prefrontal Cortex | Brain volumes |
| Greve et al. (2020) | Rats (Wistar Kyoto) | DEP | Adulthood | 1 month | 7–8/group | Male | Whole Body Inhalation | Adulthood | Hippocampus, Frontal Cortex | Microglia, inflammatory reactions |
| Haghani, Johnson, Woodward, et al. (2020) | Mice (C57BL/6J) | nPM | Prenatal | 3 weeks | Not reported | Both | Whole Body Inhalation | Adulthood | Hippocampus | Neurotransmitter or neuromodulator metabolites and receptors, inflammatory reactions, altered neurogenesis, altered cell proliferation, immune reactions |
| Hajipour et al. (2020) | Rats (Wistar) | Dusty PM | Not reported | 4 weeks | 88, 22/group | Male | Whole Body Inhalation | Not reported | Hippocampus | Synaptic changes |
| Li et al. (2020) | Mice (C57BL/6) | DEP | Adulthood | 14 days | 10/group | Male | Intranasal instillation | Adulthood | Hippocampus | Inflammatory reactions, mitochondrial changes, immune reactions, microglia |
| Liu et al. (2020) | Mice (C57BL/6) | Multiple pollutants | Adulthood | Up to 12 weeks | 72, 12/group | Male | Whole Body Inhalation | Adulthood | Hippocampus | Necrotic processes, dendritic spine length or neurite changes, inflammatory reactions, heavy metal deposits |
| Milani et al. (2020) | Mice (BALB/cOlaHsd) | DEP | Adolescence into Adulthood | Acute - single instillation, Subacute - 3 instillations | 6/group | Male | Intratracheal instillation | Adulthood | Hippocampus | Amyloid, oxidative stress markers, inflammatory reactions |
| Nephew et al. (2020) | Rats (Sprague-Dawley) | TRAP | Prenatal through Early-life | 6 weeks | 6/group | Male | Whole Body Inhalation | Early-life | Hippocampus, Anterior Cingulate | Diffusion tensor imaging |
| Park et al. (2020) | Mice (C57Bl6/J) | UFP | Adulthood | 3 weeks | 10/group | Male | Whole Body Inhalation | Adulthood | Hippocampus | Amyloid, oxidative stress markers, inflammatory reactions, |
| Patten et al. (2020) | Rats (Sprague Dawley) | TRAP | Prenatal to adulthood | 11 days | 15/group | Both | Whole Body Inhalation | Adulthood | Hippocampus | Necrotic processes, microglia, inflammatory reactions, alterations in neuronal migration, genes associated with neuronal development, altered neurogenesis, brain volumes, altered astrocytes |
| Zhou et al. (2020) | Mice (ICR) | PM2.5 | Prenatal, Early-life | 8 days | Not reported | Both | Intratracheal instillation | Childhood | Hippocampus | Altered DNA, neurotrophins |
| Ehsanifar, Jafari, et al. (2021) | Mice (NMRI) | DEP | Adulthood | 12 weeks | 48, 12/group | Male | Whole Body Inhalation | Adulthood | Hippocampus | Lipid peroxidation, neurotransmitter or neuromodulator metabolites and receptors, dendritic spine length or neurite changes, inflammatory reactions |
| Ehsanifar, Montazeri, et al. (2021) | Mice (NMRI) | DEP | Adulthood | 14 weeks | 10/group | Both | Whole Body Inhalation | Adulthood | Hippocampus | Oxidative stress markers, neurotransmitter or neuromodulator metabolites and receptors, dendritic spine length or neurite changes, inflammatory reactions, lipid peroxidation |
| Kodavanti et al. (2021) | Rats (Brown Norway) | Ozone | Adulthood, Late-life | 13 weeks | Not reported | Male | Whole Body Inhalation | Adulthood & Late-life | Frontal cortex, Hippocampus | Oxidative stress markers, mitochondrial changes |
| F. Liu et al. (2021) | Mice (ICR) | Multiple pollutants | Adulthood | 4 weeks | 6/group | Male | Intranasal instillation | Adulthood | Hippocampus, Frontal Cortex | Necrotic processes, oxidative stress markers, dendritic spine length or neurite changes, CA2+ signaling pathway-related genes, decreased number of neurons, heavy metal deposits, altered neurogenesis, neurotrophins, synaptic changes |
| Lubczynska et al. (2021) | Humans | Multiple pollutants | Prenatal through childhood | Prenatal - 9 months, Childhood - 9–12 years | 3133 | Both | Land use regression models | Childhood | Hippocampus, Amygdala | Brain volumes |
| Sahu et al. (2021) | Mice (C57BL/6;C3H) | PM2.5 | Adulthood | 3 months | Not reported | Male | Whole Body Inhalation | Adulthood | Hippocampus | No effects observed (altered astrocytes, microglia, inflammatory reactions, amyloid) |
| Wen et al. (2021) | Mice (C57BL/6) | Multiple pollutants | Prenatal | 3 months | 6/group | Both | Intratracheal instillation | Adulthood | Hippocampus | Thyroid hormone signaling pathway genes |
| Zhang et al. (2021) | Mice (SPF ICR) | PM2.5 | Prenatal | Not reported | Not reported | Both | Endotracheal nebulization | Early-life | Hippocampus | Inflammatory reactions, immune reactions |