Table 2.

In vivo effects of glyphosate and/or its commercial formulations in rodents.

Species	Dose and Exposition	Time Exposition	Objectives	Results	Reference
Swiss mice	Roundup®: 250 or 500 mg/kg/day orally	Subchronic exposition: 6 weeks Chronic exposition: 12 weeks	Assess the effects of acute or repeated GBH exposure on the developing brain of young and adult mice	Chronic/subchronic exposure: -↓ locomotion -↑ anxiety, depressive behavior -↓ 5-HT immunoreactivity Chronic exposure: ↓ TH immunoreactivity	[62]
Swiss mice	Roundup®: 250 or 500 mg/kg/day orally	Subchronic exposition: 6 weeks Chronic exposition: 12 weeks	Evaluate the effects of GBH on learning and memory functions, AChE activity, and oxidation/antioxidation homeostasis	Chronic/subchronic exposure: -Impaired recognition and retention memory -↓ AChE activity -↓ SOD and peroxidase activity Chronic exposure caused impairment in working memory	[63]
Swiss mice	Roundup®: 250 or 500 mg/kg/day orally	From GD0 to PND21	Evaluate the behavioral (PND5-PND25) and biochemical (PND60) effects of gestational and lactational exposure to GBH on offspring	-Delayed sensorimotor development from PND5 to PND25 -↓ locomotion, anxiety, ↓ sociability, cognitive impairment -↓ number of TH+ cells -↓ AChE activity -Activation of microglia and astrocytes. ↑ TNF-α expression and ↓ BDNF. ↑ TrkB levels	[64]
CF-1 mice	Glifloglex®: 50 mg/kg/day intranasally	Three days a week for four weeks	Assess the neurobehavioral effects of repeated intranasal administration of a GBH	-↓ locomotion -↑ anxiety -Impaired recognition memory	[65]
Wistar rats	Roundup®: 70 mg/kg/day orally	Chronic exposition: from GD5 to PND15. Acute exposition: 30 min in vitro	Determine the neurotoxic effects of GBH on the hippocampal function of immature rats after chronic exposure (pregnancy and lactation) and after acute in vitro exposition.	Acute in vitro exposition: -↑ glutamate release, activation of NMDAR and L-VDCC, and ↑ Ca2+ influx -CaMKII and ERK activation -LPO, ↓ GGT and G6PD activity, ↓ GSH content -↓ cellular viability Acute and chronic exposure: -Impaired glutamate metabolism in astrocytes: ↓ reuptake and metabolism, inhibition of glutamine synthetase -↑ uptake of Ca2+ -↑ accumulation of C-MeAIB	[37]
Wistar rats	Roundup®: 1% in drinking water (0.38% GLY)	Subchronic exposition: from GD5 to PND21. Chronic exposition: from GD5 to PND60.	Investigate the effects of subchronic exposure to GBH on neurochemical and behavioral parameters in immature and adult offspring	-↓ uptake and ↑ glutamate release -Activation of NMDARs and influx of Ca2+ -GLY can bind to the glutamate and glycine cavities of NMDAR -↓ AChE activity in offspring -Depressive behavior -↓ levels of GSH (acute exposure) -↓ GST after acute exposure, ↑ after chronic exposure -↓ SOD and G6PD activity -ERK1/2 overactivation -↓ NF-kB activation -↓ levels of S100B protein during development, which later increased in adult offspring	[3]
Wistar rats	Roundup®: 70 mg/kg/day orally	Subchronic exposition: from GD5 to PND15.	Investigate possible biochemical and cell-persistent effects in the brain of adult rats following perinatal exposure to GBH	-Changes in the peptide expression in the SN -↓ expression of peptides from the dynorphin family -↓ dynorphin immunoreactivity in the SN and hippocampus -↑ number of nestin-positive hippocampus cells	[66]
Wistar rats	GLY: 24 or 35 mg/kg intraperitoneally	Dams received injections every 48 h from GD8 to GD20, totaling seven injections over two weeks	Evaluate the neurobehavioral effects of GLY in neonate rats after gestational exposure	-Delay in the development of neonatal reflexes in offspring -↓ locomotion -Learning and memory deficits -Negative regulation of the Wnt5a/CaMKII pathway	[67]
Sprague-Dawley rats	GLY, Roundup®: 5 mg/kg/day orally	From GD10 to PND22	Compare the potential effects of a low dose of GLY and GBH on maternal behavior and maternal neuroplasticity, focusing on the hippocampus and cingulate gyrus	-Initial reduction in maternal licking behavior, followed by a subsequent increase -Impairment of neurogenesis and plasticity in the mother’s hippocampus -Alteration in synaptophysin expression	[68]
CF-1 mice	Glifloglex®: 50 mg/kg/day intranasally	Four weeks (three injections per week)	Elucidate the mechanisms by which the intranasal administration of a GBH exerts its neuropathological effects	-↓ total thiol content and CAT activity -↓ expression of ChAT and α7 nAChRs and AChE activity -↑ number of astrocytes -↓ GPT and GOT transaminase activity	[69]
Sprague-Dawley rats	GLY: 50, 100, or 150 mg/kg intraperitoneally	Two weeks (three injections per week)	Assess the integrity of the nigrostriatal and mesolimbic dopaminergic systems and their relationship with spontaneous locomotor activity after repeated or acute exposure to GLY	-↓ locomotion in the short term -↓ specific binding of an antagonist to dopamine D1 receptors in the short term -↓ levels of extracellular dopamine in the short term	[70]
ICR mice	Roundup®: 50 mg/kg/day orally	From GD14 to PND7	Assess the miRNA expression patterns in the PFC of mouse offspring after exposure to GBH during pregnancy and lactation	-Dysregulation of 53 miRNAs involved in brain development and in the pathogenesis of non-destructive diseases	[71]
Balb/c mice	Roundup®: 25, 50 or 100 mg/kg orally	Acute exposure	Investigate the behavioral effects induced by acute exposure to a GBH in increasing doses	-↓ exploratory capacity of females -↑ immobility time	[72]
Wistar rats	GBH: 2.5, 5, 10, 20 or 40 mM	Single dose	Assess the inhibitory potency of a GBH on AChE activity in rat tissues	-GBH is a weak inhibitor of AChE activity	[73]
Wistar rats	GLY: 35 or 70 mg/kg subcutaneous injection	From PND7 to PND27	Evaluate the effects of glyphosate on hippocampal synapses and cognitive functioning	-Impairment of spatial memory and recognition -↓ expression of CAMKII -↓ expression of synaptic proteins	[74]
Wistar rats	GLY: 35, 75, 150 or 800 mg/kg/day orally	Six days	Determine the effects of GLY on the levels of DA, NE, and 5-HT and their metabolites, as well as the turnover in striatum, hippocampus, PFC, hypothalamus, and midbrain.	-Significant dose- and region-dependent decreases in 5-HT, DA, and NE contents -↑ turnover of 5-HIAA/5-HT in the striatum and DOPAC+HVA/DA in the PFC and hippocampus -↓ turnover of NE/MHPG in the PFC and hypothalamus	[13]

Abbreviations: GBH, glyphosate-based herbicide; ↓, decrease; ↑, increase; 5-HT, serotonin; TH, tyrosine hydroxylase; AChE, acetylcholinesterase; SOD, superoxide dismutase; GD, gestational day; PND, postnatal day; TNF-α, tumor necrosis factor alpha; BDNF, brain-derived neurotrophic factor; TrkB, tyrosine-related kinase receptor B; NMDAR: N-methyl-D-aspartate receptor; L-VDCC, voltage-dependent calcium channels; CaMKII, Ca2+/calmodulin-dependent protein kinase II; ERK, extracellular signal-regulated kinases; LPO, lipid peroxidation; GGT, gamma-glutamyl transferase; G6PD, glucose-6-phosphate dehydrogenase; GSH, glutathione; C-MeAIB, C-methylaminoisobutyric acid; GLY, glyphosate; GST, glutathione S-transferase; NF-kB, nuclear factor-kB; S100B, S100 calcium-binding protein B; SN, substantia nigra; CAT, catalase; ChAT, choline acetyltransferase; nAChRs, nicotinic acetylcholine receptors; GPT, glutamate-pyruvate transaminase; GOT, glutamate-oxaloacetate transaminase; PFC, prefrontal cortex; DA, dopamine; NE, noradrenaline; 5-HIAA, 5-hydroxyindoleacetic acid; DOPAC, 3,4-dihydroxyphenylacetic acid; HVA, homovanillic acid; MHPG, methoxy-4-hydroxyphenylglycol.