Memory and Cognition-Related Neuroplasticity Enhancement by Transcranial Direct Current Stimulation in Rodents: A Systematic Review

Abstract

Brain stimulation techniques, including transcranial direct current stimulation (tDCS), were identified as promising therapeutic tools to modulate synaptic plasticity abnormalities and minimize memory and learning deficits in many neuropsychiatric diseases. Here, we revised the effect of tDCS on the modulation of neuroplasticity and cognition in several animal disease models of brain diseases affecting plasticity and cognition. Studies included in this review were searched following the terms (“transcranial direct current stimulation”) AND (mice OR mouse OR animal) and according to the PRISMA statement requirements. Overall, the studies collected suggest that tDCS was able to modulate brain plasticity due to synaptic modifications within the stimulated area. Changes in plasticity-related mechanisms were achieved through induction of long-term potentiation (LTP) and upregulation of neuroplasticity-related proteins, such as c-fos, brain-derived neurotrophic factor (BDNF), or N-methyl-D-aspartate receptors (NMDARs). Taken into account all revised studies, tDCS is a safe, easy, and noninvasive brain stimulation technique, therapeutically reliable, and with promising potential to promote cognitive enhancement and neuroplasticity. Since the use of tDCS has increased as a novel therapeutic approach in humans, animal studies are important to better understand its mechanisms as well as to help improve the stimulation protocols and their potential role in different neuropathologies.

Whole Blood Transcriptome Characterization of 3xTg-AD Mouse and Its Modulation by Transcranial Direct Current Stimulation (tDCS)

“…As a proof of the principle that brain stimulations have an effect on the brain with consequences that can also be observed at the peripheral level, we studied the blood transcriptome profile of mice that underwent anodal tDCS. tDCS has been largely studied for its effects on synaptic plasticity and neuronal excitability [ 16 , 17 ], and different studies in animal models have shown its effects on brain gene expression. In rat cerebral cortices, the administration of tDCS was observed to modulate the expression of several genes involved in synaptic plasticity, such as neurotransmitter receptors [ 22 ], plasticity related genes [ 71 ], and genes coding for the major histocompatibility complex I [ 21 ].…”

“…tDCS is a noninvasive brain stimulation technique that is able to modulate cortical excitability through the release of a weak electrical current. In particular, anodal stimulation is known to depolarize neurons, to increase the probability of action potentials occurring and to induce synaptic plasticity [ 16 , 17 , 18 ]. The effects of tDCS on brain gene expression have been previously assessed in different animal models, revealing its ability to modulate the expression of genes involved in the mechanisms of synaptic plasticity and neuronal activity [ 19 , 20 , 21 , 22 ]; however, to date no studies have investigated its effects at the blood level.…”

Effects of Transcranial Direct Current Stimulation (tDCS) in the Normalization of Brain Activation in Patients with Neuropsychiatric Disorders: A Systematic Review of Neurophysiological and Neuroimaging Studies

“…We examined this phenomenon by understanding the possible neuronal mechanisms of tDCS. Increasing direct evidence from animal studies has shown that tDCS could moderate NMDAR-dependent synaptic plasticity (see Cavaleiro et al [ 79 ] for a review), and human magnetic resonance spectroscopy (MRS) studies showed that tDCS could modulate the concentration of gamma-aminobutyric acid (GABA), a neurotransmitter acting at inhibitory synapses in the brain [ 80 ]. This translational evidence leads to the hypothesis that tDCS might bring about specific behavioral changes by moderating synaptic plasticity of the stimulated brain regions as well as the functionally connected networks [ 81 ].…”

The Role of Acupuncture Improving Cognitive Deficits due to Alzheimer’s Disease or Vascular Diseases through Regulating Neuroplasticity

“…It is known that dysregulated or disrupted neuroplasticity is implicated as a pathological mechanism in AD [ 15 ] and VCI [ 16 ]. Furthermore, some treatments that stimulate or modulate neuroplasticity have been indicated as effective in improving cognition [ 12 , 17 , 18 ], and might be potential therapy in cognitive impairments such as AD and VCI.…”