Endogenous electric fields

Endogenous electric fields were measured at human skin wounds in the mid-nineteenth century. German physiologist Emil Du-Bois Reymond, using a self-built galvanometer, measured electric currents of 1 pA flowing out of a skin wound on his own finger (1, 2). 

Fig. 1. Endogenous electric fields at epithelial wounds, (a) Schematic showing electric current flow (arrows) driven out the wound site by the transepithelial potential difference. (b) Small cut on human finger tip (/efl) and vibrating probe measuring current at the wound site (right), (c) Electrical currents at human finger wound, (b, c) are modified from (6).

Nuccitelli, R. (2003) Endogenous electric fields in embryos during development, regeneration and wound healing. Radiat. Prot. Dosimetry 106, 375-383. 

Nuccitelli, R., A role for endogenous electric fields in wound heahng. Curr. Top. Develop. Biol., 2003,58 1-26. 

As opposed to the two other endogenous excitatory amino acid candidates, cystelc acid and cysteine sulphinlc acid (15), glutamate (16) and aspartate (13) are found in abundant quantities in the mammalian CNS. Metabolically, aspartate and glutamate are related and their metabolism is quite complex. Thus, there are undoubtedly several metabolic pools of glutamate and aspartate, in addition to any neurotransmitter pool, making it difficult to study the biochemical aspects of their neurotransmitter action. Nevertheless, it has been shown that both substances are accumulated into brain tissue by a high affinity process, and that both can be released from brain tissue by electrical field stimulation. This behavior is characteristic of neurotransmitters. 

Key words Electrical fields. Endogenous electric signals. Directional ceU migration. Wound heaUng... 

Nuccitelli, R. (1992) Endogenous ionic currents and DC electric fields in multicellular animal tissues. Bioelectromagnetics Suppl 1, 147-157. 

All electric currents are accompanied by magnetic fields. With the invention of the Superconducting Quantum Interference Device as an extremely low magnetic field (10 T) detector, it has become possible to measure the magnetic fields from the small endogenic currents of the body, even from the small sources in the heart and the central nervous system. This has opened up a whole new field of measurements analogous to their electric counterparts MKG (EKG), MEG (EEG), and so on. However, these interesting subjects are outside the scope of this book, and the reader is referred to the book by Malmivuo and Plonsey (1995). 

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