Guidance by Galvanotaxis - Mechanisms of Morphogenesis - page 109

CHAPTER
10
Guid ance by Galvano taxis
Galvanotaxis, the guidance of cells by electric fields, has long been a Cinderella subject in
developmental biology. The ability of electric fields to guide cells has been shown convin-
cingly in culture, and there is good evidence for the existence of electric fields in vivo ; for
these reasons, galvanotaxis is championed as a developmental mechanism by a small band
of enthusiasts. Nevertheless, it is generally ignored in texts and reviews of development,
largely because of an enduring suspicion that although electric fields have the potential to
steer cells, they are not used for this purpose by real embryos. There is not yet enough
evidence to settle whether galvanotaxis is widely used in development but there is enough
to justify this brief review of what may soon be seen to be an important mechanism in devel-
opment or at least an important tool in tissue engineering. 1
CEL L MOVEMENT IN RESPONSE TO ELECTRIC FIE LDS
Many migratory cell types will respond galvanotactically to electric fields in culture
( Figure 10.1 ). When a small DC field of 600V/m is applied to a culture of embryonic quail
FIGURE 10.1 Galvanotactic response of neurites to a DC electric field. (a) In the absence of an external field,
neurites grow equally well in all directions from an embryonic ganglion placed in culture; (b) in the presence of an
electric field, their direction of growth is biased, typically towards the cathode. That neurites growing towards the
cathode are longer than controls with no field is also typical, at least for most tissue culture substrates.