Effect of transcranial direct current stimulation on Notch pathway activation and functional recovery promotion in stroke rats

Clinical studies show that transcranial direct current stimulation (tDCS) in the intersections of the bilateral supraorbital foramen and inferior orbital rim and nose is helpful for rehabilitation after stroke. However, the neurobiological mechanism of tDCS is poorly understood. Here we focus on the effect of tDCS on functional recovery and Notch signaling pathway after stroke. Middle cerebral arterial occlusion (MCAO) reperfusion is induced in rats. Animals with comparable infarcts are randomly divided into ischemia group (MCAO) and post-ischemia treatment group (MCAO + tDCS). Neural system severity score (mNSS) combined with animal behavioral performance is used to evaluate the recovery of neural function. TTC (2,3,5-triphenyltetrazolium chloride) staining is applied to compare histologically the recovery of ischemic tissue injury before and after treatments. Real-time quantitative polymerase chain reaction (RT-PCR) is used to determine mRNA expression changes of receptor protein, ligand protein, and downstream factor in the Notch signaling pathway in ischemic brains. The results reveal that ischemia could activate Notch signaling pathway, tDCS treated by multilead brain reflex instrument could facilitate mRNA expression of Notch1, NICD, RBP-JK and Hes-1, promote the recovery of neurological function, and significantly reduce the volume of cerebral infarct. Our study suggests that tDCS with multi-lead brain reflex instrument can be expected to become a reliable clinical treatment.