  The soliton wave model of action potentials, and the proposal of induced
lipid pores, are potentially paradigm shifting ideas which challenge accepted
views of the Hodgkin-Huxley model and of protein-based ion channels. These two
proposals are reviewed, and possible tests of each are presented. Also, three
key non-electrical features seen during action potentials are reviewed; a shift
in birefringence, the pattern of heat emission and absorption, and the
expansion of cell diameter. How the soliton wave model uses the lipid phase
transition to account for each of these three phenomena is contrasted with
alternatives which might be consistent with the Hodgkin-Huxley model of action
potentials. It is suggested that changes in membrane potential during the
action potential might have a significant effect on membrane proteins and
contribute to the production of each of these phenomena. A key assumption of
the soliton wave model is that lipid phase transitions are common and adaptive
in life. However a review of the literature suggests that often lipid phase
transitions are damaging to cells, and so are often avoided. There is a need
for clearer evidence as to whether or not neurons actually do have liquid
crystalline to gel lipid phase transitions happening in them during action
potentials, as the soliton model assumes. Several major paradigm shifts are
associated with the soliton wave model, and with the proposal of induced lipid
pores, and such large claims require additional testing and a great deal of
supportive evidence if they are to achieve broader acceptance.
