Effect of weak alternating magnetic fields on planarian regeneration.

We investigated the effect of weak combined magnetic field (CMF) on stem cell proliferation and regeneration of the planarian Schmidtea mediterranea. CMF parameters were set in accordance with Valery Lednev's theory of magnetic parametric resonance. It was shown that CMF with an amplitude of 74 μT and a frequency of 30 Hz accelerated the growth of the planarian head blastema by 25%. Alterations of the frequency in range from 27 to 33 Hz led to a complete disappearance of the effect. A further decrease in the CMF frequency inhibited regeneration. The maximum inhibition (24%) was observed at a frequency of 16 Hz. A further decrease in the CMF frequency (down to 13 Hz) led to disappearance of the described effect. Regeneration rate changes under the CMF are influenced by alterations in stem cell mitotic activity, which in turn depends on the wound-induced gene expression level. Thus, the CMF, preset in accordance to the Lednev's theory, can specifically influence the expression of regeneration-related genes and regeneration itself, what can find biomedical applications.