This study investigates the effects of transcranial magnetic stimulation (TMS) on cellular energetics using a differentiated SH-SY5Y neural cell model.
To explore this, SH-SY5Y neuroblastoma cells were differentiated into a more mature neural phenotype using BrainPhys™ neuronal medium supplemented with Penicillin/Streptomycin, a serum- and antioxidant-free B-27™ supplement, 50 ng/ml BDNF, and 10 µM retinoic acid. Following differentiation of 7 days, cells were seeded in 35 mm Petri dishes and placed 1 cm below the center of a TMS coil. The stimulation parameters were applied as described by Thomson and colleagues (2020), with stimulation at 100% Maximum Stimulator Output. Intermittent theta-burst stimulation (iTBS) consisted of 50 Hz triplets repeated in a 5 Hz rhythm in 2-second trains with 8-second inter-train intervals, while continuous theta-burst stimulation (cTBS) was applied as a continuous train, both for 600 pulses.
To assess the effects of iTBS and cTBS on mitochondrial respiration, the Agilent Seahorse Cell Mito Stress Test kit was used. The results indicated that cTBS had no significant effects on oxygen consumption rate (OCR), while iTBS stimulation led to an increase in maximal respiration and spare capacity values. Additionally, reactive oxygen species (ROS) production was evaluated using the DCFDA/H2DCFDA Cellular ROS Assay Kit (Abcam). The results showed a 1.5-fold downregulation of ROS levels following iTBS stimulation. These findings suggest that iTBS enhances mitochondrial function and reduces oxidative stress in the SH-SY5Y neural cell model, whereas cTBS does not significantly affect these parameters. Further research is needed to understand the molecular mechanisms behind these changes and their potential therapeutic applications.