In vivo modulation of stem cell recruitment and proliferation via bi‐phasic electrical stimulation

Abstract

Tissue regeneration is dependent upon cellular ion channels that may be activated by electrical fields (EF). Modulation of EFs by electrical stimulation (ES) and/or pharmacological ion channel manipulation can either inhibit or induce regeneration in tissues with regenerative capacity. Either bi‐phasic or direct current ES can evoke migration, proliferation and differentiation of stem cells (SC) in vitro. This study hypothesizes that exogenous ES increases the activity of dedifferentiated and resident SC in vivo via activation of ion channel signaling. Bi‐phasic ES (2 volts, 2 Hz) of the skeletal muscle in fresh water crayfish Procambarus clarkii was conducted using implanted electrodes near the distal end of the abdomen. ES was conducted at 24 hours on/off over four cycles (Group I), continuously over 4 days (Group II) and in sham electrode implanted animals (Group III & IV; no stimulation). Relative abundance of SC was quantified by densitometry. Cyclic ES increased SC density (8.69±2.9 units; Group I) over sham experiments (2.03±0.49 units, Group III; P<0.05). Similarly, continual ES increased SC density (3.728±1.1 units, Group II vs. 1.032±0.52 units, Group IV; p<0.05). Thus, in vivo low‐level ES induces SC proliferation similar to previous in vitro studies. Current studies are investigating how pharmacological inhibition of ion channels may alter this effect and how ES changes genomic expression of SC.