Theta burst stimulation influence the expression of BDNF in the spinal cord on the experimental autoimmune encephalomyelitis.

Abstract

Repetitive transcranial magnetic stimulation (rTMS) induces changes in expression of proteins engaged in the activity of excitatory and inhibitory systems, restores these functions and suppresses the progression of disability in experimental autoimmune encephalitis (EAE). The structural type of TMS, the arrangement as theta burst stimulation (TBS) has been applied as intermittent TBS (iTBS) and continuous TBS (cTBS) protocols to female adult DA rats. The animals were randomly divided into experimental groups: control group (C), group treated with complete Freund's adjuvant (CFA), experimental autoimmune encephalomyelitis (EAE) group, group treated with iTBS post EAE immunization (EAE + iTBS), group treated with cTBS post EAE immunization (EAE + cTBS), group of healthy animals treated with iTBS or cTBS. Therapeutic protocols of iTBS or cTBS in all EAE groups of animals were performed starting from 14 days post immunization (dpi), for 10 days with time point decapitation at 24 dpi. After decapitation, spinal cords were analysed for BDNF and Ki67 expression. The results revealed reduced BDNF expression in the rat's spinal cord of EAE animals in the stage of remission, which was associated with increased Ki67 and GFAP expressions. Decreased Iba 1 and BDNF expression, contrary to increased Iba 1 and Ki67 expression, suggests clustered microglia in the resolution phase of EAE. Enhanced GABA expression in spinal cord sections indicates higher GABA metabolic turnover, and also GAD activity in astrocytes, or prominent activity of GABAergic neurons. Both TBS protocols induced advance BDNF expression; amongst iTBS application provoked elevating of BDNF and stabilizing of GFAP and Ki67 expressions.