The effect of magnetic stimulation on astrocyte migration and its mechanism / 中华物理医学与康复杂志

ABSTRACT

Objective To investigate the effect of magnetic stimulation on astrocyte migration and its mech-anism. Methods Twenty-four adult, healthy Spragne-Dawley rats were injected with 0.5 μl of 1% ethidium bro-mide (EB) in the left side of the dorsal spinal cord funiculus at the T_(10-11) level to make a local spinal cord injury mod-el. They were then randomly divided into four groups and exposed to 30 pulses of magnetic stimulation at 1 Hz and the following intensities O T (Group A);1.9x40% T (Group B); 1.9x80% T (Group C); 1.9x100% T (Group D). On the 14th day after stimulation, the rats were sacrificed and the expression of glial fibrillary acidic protein (GFAP), microtubule associated protein-2 (MAP-2) and extracellular signal-regulated kinase 1/2 (ERK 1/2) were detected, and the volume of holes in the injured area of the spinal cord was measured. Quantitative analysis of the GFAP, MAP-2 and ERK1/2 expression was performed using immunohistochemistry and an image anal-ysis system. Results The volume of holes in the injured area of the spinal cord decreased with increasing stimula tion intensity. In the reduced area of the holes, the expression of GFAP and ERK 1/2 could be seen, but not MAP-2. Significant differences were revealed in the expression of GFAP and ERK 1/2 among the four groups, but it was always significantly higher in the magnetic stimulation groups than in the controls. Conclusions After magnetic stimulation, astrocytes migrate into the injured spinal cord's holes. Astroeyte migration increases with increased mag-netic stimulation intensity, which may be associated with high expression of ERK 1/2.