Author Year Animal model Specimen; gender Stimulation parameters Main findings Stimulation electrode Reference electrode Anesthesia rtDCS Polarity Position Stimulation intensity (mA) Size (cm2 ) Stimulation duration (min) Current density (A/m2 ) Position Area (cm2 ) Kamida et al. [32 ] 2011 Lithium-pilocarpine hydrochloride (60 mg/kg) SC injection at P20-21 Wistar rats; males 18 c-tDCS Hippocampus 0.2 0.035 30 N/A Back of neck N/A N Y (daily for 2 weeks) ↓ SE-induced hippocampal cell loss in CA3 region Yu et al. [43 ] 2014 Scopolamine IP injection Sprague Dawley rats; both genders 16 N/A Parietal cortex (hippocampus) 0.1 N/A 20 N/A N/A N/A N/A Y (2x/day during 5 days a week, for 4 weeks) ↓ Time and ↓ number of errors to reach food pellets Significant differences in ACh content (day 14 and day 28) ↑ Motor function Pedron et al. [49 ] 2014 Nicotine IP injection (1 mh/kg 2x/day for 14 days) Swiss mice; females 152 a-tDCS Left frontal cortex 0.2 0.035 N/A Ventral thorax 9.5 N Y (5 days) ↑ Working memory ↑ Nicotine-induced place preference conditioning (3 weeks poststimulation) Yu et al. [30 ] 2015 Bilateral hippocampus Aβ 1-40 injection Sprague Dawley rats; females 36 a-tDCS Right frontal cortex 0.02; 0.06; 0.1; 0.2 0.0314 20 N/A Ventral thorax 10 N Y (10 sessions in 2 weeks) ↑ Spatial learning performance (best with 0.1 mA and 0.2 mA stimulation) ↓ GFAP expression in CA1 hippocampus region and DG (best with 0.1 mA stimulation) Yoon et al. [31 ] 2016 Lateral fluid percussion method Sprague Dawley rats; males 36 a-tDCS Hippocampus 0.2 0.0225 20 28.2 Chest 48 (corset) Y Y (daily for 5 days) ↑ Perilesional area BDNF expression (tDCS 2 weeks post-TBI) ↑ Choline/creatinine ratios (tDCS 1 week post-TBI) Motor performance recovery (2 weeks of tDCS) Leffa et al. [33 ] 2016 SHR SHR rats and WKT rats; males 48 a-tDCS Frontal cortex 0.5 1.5 20 33.4 Between ears 1.5 N Y (8 consecutive days) ↑ DA levels in STR in both rat strains and in the hippocampus following tDCS treatment in WKY ↑ BDNF levels in WKY rats Short-term memory improvement Wu et al. [45 ] 2017 STZ-induced diabetic rats Sprague Dawley rats; males 130 a-tDCS dPFC 0.2 0.0314 30 N/A Anterior chest 0.25 Y Y ↑ Spatial working memory and mPFC LTP restoring Pedron et al. [50 ] 2017 Cocaine injections Swiss mice; females 165 a-tDCS Left frontal cortex 0.2 0.035 N/A Ventral thorax 9.5 N Y (5 days stimulation, twice a day; 5 h interstimulation interval) ↓ Cocaine-induced locomotor activity No cocaine-induced place preference (5 mg/kg and 25 mg/kg) ↑ Zif268 basal expression under the electrode area, in the STR and cortex Leffa et al. [55 ] 2018 ADHD SHR and WKY rats; males 30 a-tDCS (bicephalic) Frontal cortex (supraorbital area) 0.5 1.5 (ECG electrode) 20 33.3 Neck 1.5 (ECG electrode) N/A Y (8 days) ↓ Inflammatory cytokines and reversion of long-term memory deficits in SHR rats Bragina et al. [47 ] 2018 CCI Mice; N/A 40 a-tDCS Parietal somatosensory cortex 0.1 N/A 15 N/A Ventral thorax N/A N/A Y (daily for 4 days, over 4 weeks and 3 days interval) Motor coordination recovery Spatial memory and learning performance improvement ↑ CBF bilaterally (regional arteriolar dilatation and hypoxia reduction) Roostaei et al. [44 ] 2019 STZ-induced diabetic rats Wistar rats; males 64 a-tDCS vs. c-tDCS Left frontal cortex 0.2 3.5 20 N/A Ventral thorax 9.5 N Y (twice a day over 2 days) Restoration of STZ-induced amnesia (both polarities) Gondard et al. [55 ] 2019 Animal model of AD-triple transgenic (3xTg) mice Triple transgenic (3xTg) mice; males 27 c-tDCS and a-tDCS Secondary motor cortex (m2) (c-TDCS) and dorsal temporal hippocampus (a-tDCS) 0.05 0.0325 20 N/A N/A 0.0325 N/A Y (5 days/week for 3 weeks) No treatment effect on memory outcome or AD neuropathological biomarkers