Transcranial magnetic stimulation in animal models of neurodegeneration

Abstract

Brain stimulation techniques offer powerful means of modulating the physiology of specific neural structures. In recent years, non-invasive brain stimulation techniques, such as transcranial magnetic stimulation (TMS) and transcranial direct current stimulation, have emerged as therapeutic tools for neurology and neuroscience. However, the possible repercussions of these techniques remain unclear, and there are few reports on the incisive recovery mechanisms through brain stimulation. Although several studies have recommended the use of non-invasive brain stimulation in clinical neuroscience, with a special emphasis on TMS, the suggested mechanisms of action have not been confirmed directly at the neural level. Insights into the neural mechanisms of non-invasive brain stimulation would unveil the strategies necessary to enhance the safety and efficacy of this progressive approach. Therefore, animal studies investigating the mechanisms of TMS-induced recovery at the neural level are crucial for the elaboration of non-invasive brain stimulation. Translational research done using animal models has several advantages and is able to investigate knowledge gaps by directly targeting neuronal levels. In this review, we have discussed the role of TMS in different animal models, the impact of animal studies on various disease states, and the findings regarding brain function of animal models after TMS in pharmacology research.

Intermittent theta burst stimulation attenuates oxidative stress and reactive astrogliosis in the streptozotocin-induced model of Alzheimer’s disease-like pathology

“…One of the factors shown to initiate Nrf2 translocation is BDNF ( Bruna et al, 2018 ; Davies et al, 2021 ), whose expression is proven to be modulated by rTMS ( Stevanovic et al, 2019 ). Our results demonstrated TMS-mediated elevation of both Nrf2 and BDNF, which might partially explain the improvement of overall oxidative status ( Numakawa et al, 2018 ; Liang et al, 2021 ; Uzair et al, 2022 .) following STZ administration.…”

“…In developing antioxidant therapies for neurological disease, special attention should be given to the brain’s unique vulnerability of the brain to oxidative insults and its architecture ( Birngruber et al, 2013 ). rTMS has been postulated as a promising therapeutic approach in the treatment of neurodegenerative disorders, through the production of complex neurobiological effects such as induction of early genes, changes in Ca 2+ dynamics, reduction of oxidative stress and inflammation, and activation of neurotrophic factors ( Uzair et al, 2022 ). Herein, we applied iTBS, a highly efficient protocol of rTMS, to evaluate its effect on oxidative stress and the promotion of antioxidative capacity.…”

“…Other studies carried out in rat models of Huntington’s disease ( Túnez et al, 2006 ) and olfactory bulbectomy ( Tasset et al, 2010 ) corroborate the antioxidant actions of rTMS, suggesting that it may be mediated through the Nrf2 pathway. Furthermore, it has been shown that rTMS may improve mitochondrial viability ( Medina-Fernandez et al, 2017 ), which is a significant source of reactive oxygen species, and attenuate pro-apoptotic cascade improving cellular viability in general ( Uzair et al, 2022 ). Interestingly, both BDNF and Nrf2 are involved in synaptic plasticity, learning, and memory which are impaired in STZ-induced neurotoxicity ( Singh and Garabadu, 2021 ; Tiwari et al, 2021 ; Stanojevic et al, 2022 ).…”

Brain stimulation for chronic pain management: a narrative review of analgesic mechanisms and clinical evidence

“…This is achieved by transmitting a strong current through a wire from a machine to a circular wire, which initiates a magnetic field in a perpendicular direction based on Faraday’s law of induction. When the circular wire is applied to the scalp, the time-changing magnetic field induces the current in the axons beneath the scalp, running in the opposite direction to the current in the coil, thereby stimulating the brain tissue [ 142 ].…”

“…HF-rTMS can increase cortical excitability, and MEP size (i.e., motor-evoked potential, electric potential in the motor pathway induced by TMS) [ 144 ], and provoke intercellular interactions. As a result, it can enhance and facilitate cell proliferation, focal cerebral blood flow, and synaptic plasticity [ 142 ].…”