title: The Effects of Different Repetitive Transcranial Magnetic Stimulation (rTMS) Protocols on Cortical Gene Expression in a Rat Model of Cerebral Ischemic-Reperfusion Injury.
abstract: Although repetitive Transcranial Magnetic Stimulation (rTMS) in treatment of stroke in humans has been explored over the past decade the data remain controversial in terms of optimal stimulation parameters and the mechanisms of rTMS long-term effects. This study aimed to explore the potential of different rTMS protocols to induce changes in gene expression in rat cortices after acute ischemic-reperfusion brain injury. The stroke was induced by middle cerebral artery occlusion (MCAO) with subsequent reperfusion. Changes in the expression of 96 genes were examined using low-density expression arrays after MCAO alone and after MCAO combined with 1Hz, 5Hz, continuous (cTBS) and intermittent (iTBS) theta-burst rTMS. rTMS over the lesioned hemisphere was given for two weeks (with a 2-day pause) in a single daily session and a total of 2400 pulses. MCAO alone induced significant upregulation in the expression of 44 genes and downregulation in 10. Two weeks of iTBS induced significant increase in the expression of 52 genes. There were no downregulated genes. 1Hz and 5Hz had no significant effects on gene expression, while cTBS effects were negligible. Upregulated genes included those involved in angiogenesis, inflammation, injury response and cellular repair, structural remodeling, neuroprotection, neurotransmission and neuronal plasticity. The results show that long-term rTMS in acute ischemic-reperfusion brain injury induces complex changes in gene expression that span multiple pathways, which generally promote the recovery. They also demonstrate that induced changes primarily depend on the rTMS frequency (1Hz and 5Hz vs. iTBS) and pattern (cTBS vs. iTBS). The results further underlines the premise that one of the benefits of rTMS application in stroke may be to prime the brain, enhancing its potential to cope with the injury and to rewire. This could further augment its potential to favorably respond to rehabilitation, and to restore some of the loss functions.
authors.affiliation: Department of Physiology, College of Medicine and Health Sciences, UAE University, Al Ain, UAE.
authors.forename: Milos R
authors.initials: MR
authors.lastname: Ljubisavljevic
authors.affiliation: Department of Physiology, College of Medicine and Health Sciences, UAE University, Al Ain, UAE.
authors.forename: Asma
authors.initials: A
authors.lastname: Javid
authors.affiliation: Department of Physiology, College of Medicine and Health Sciences, UAE University, Al Ain, UAE.
authors.forename: Joji
authors.initials: J
authors.lastname: Oommen
authors.affiliation: Department of Physiology, College of Medicine and Health Sciences, UAE University, Al Ain, UAE.
authors.forename: Khatija
authors.initials: K
authors.lastname: Parekh
authors.affiliation: Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Queen Elizabeth Central Hospital, College of Medicine, Blantyre, Malawi; Department of Community Medicine, College of Medicine and Health Sciences, UAE University, Al Ain, UAE.
authors.forename: Nico
authors.initials: N
authors.lastname: Nagelkerke
authors.affiliation: Department of Anatomy, College of Medicine and Health Sciences, UAE University, Al Ain, UAE.
authors.forename: Safa
authors.initials: S
authors.lastname: Shehab
authors.affiliation: Department of Physiology, College of Medicine and Health Sciences, UAE University, Al Ain, UAE.
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Adrian
mesh_terms: D000818:Animals; D001921:Brain / Q000503:physiopathology*; D004195:Disease Models, Animal; D019054:Evoked Potentials, Motor / Q000235:genetics*; D015870:Gene Expression / Q000235:genetics*; D008297:Male; D009473:Neuronal Plasticity / Q000235:genetics; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000235:genetics*; D020521:Stroke / Q000235:genetics; D009435:Synaptic Transmission / Q000235:genetics; D013826:Theta Rhythm / Q000235:genetics; D050781:Transcranial Magnetic Stimulation / Q000379:methods