Investigations of nerve activity have focused predominantly on electrical phenomena.
Nerves, however, are thermodynamic systems, and changes in temperature and in the
dimensions of the nerve can also be observed during the action potential. Measurements of
heat changes during the action potential suggest that the nerve pulse shares many
characteristics with an adiabatic pulse. First experiments in the 1980s suggested small
changes in nerve thickness and length during the action potential. Such findings have led to …

Investigations of nerve activity have been focused predominantly on electrical phenomena. It
is to be expected that the state of the nerve cell depend not only on electrochemical
potentials and the conjugated flux of ions but also on all other thermodynamic forces
including variations in lateral pressure, resulting in changes of membrane area and
thickness (1-2) and temperature, resulting in heat flux (3).While both mechanical and
thermal signals are very small, they are found to be in phase with voltage changes. Such …