Low intensity repetitive magnetic stimulation reduces expression of genes related to inflammation and calcium signalling in cultured mouse cortical astrocytes

Repetitive transcranial magnetic stimulation (rTMS) is a form of non-invasive brain frequently used to induce neuroplasticity in the brain. Even at low intensities, rTMS has been shown modulate aspects neuronal plasticity such as motor learning and structural reorganisation neural tissue. However, impact intensity on glial cells astrocytes remains largely unknown. This study investigated changes RNA (qPCR array: 125 selected genes) protein levels (immunofluorescence) cultured mouse following single session repetitive (LI-rMS – 18 mT). Purified neonatal cortical astrocyte cultures were stimulated with either 1Hz (600 pulses), 10Hz or 6000 pulses) sham (0 LI-rMS, followed by extraction 5 h post-stimulation, fixation 24-h post-stimulation. LI-rMS resulted two-to-four-fold downregulation mRNA transcripts related calcium signalling (Stim1 Orai3), inflammatory molecules (Icam1) (Ncam1). reduced expression Stim1, Orai3, Kcnmb4, Ncam1 mRNA, whereas Icam1 signalling-related genes. Protein similar pattern for rMS, significant reduction STIM1, ORAI3, KCNMB4, NCAM1 compared sham, but increased STIM1 ORAI3 relative sham. These findings demonstrate ability specific astrocytic phenotype, potentially contributing known effects excitability neuroplasticity.