This book represents the proceedings of a NATO Advanced Research
Workshop of the same name, held at St. Andrews University, Scotland in
July of 1989. It was the first meeting of its kind and was convened as a
forum to review and discuss the phylogeny of some of the cell biological
functions that underlie nervous system function, such matters as
intercellular communication in diverse, lower organisms, and the
electrical excitability of protozoans and cnidarians, to mention but
two. The rationale behind such work has not necessarily been to
understand how the first nervous systems evolved; many of the animals in
question provide excellent opportunities for examining general questions
that are unapproachable in the more complex nervous systems of higher
animals. Nevertheless, a curiosity about nervous system evolution has
invariably pervaded much of the work. The return on this effort has been
mixed, depending to a large extent on the usefulness of the preparation
under examination. For example, work on cnidarians, to many the keystone
phylum in nervous system evolution simply because they possess the
"first" nervous systems, lagged behind that carried out on protozoans,
because the latter are large, single cells and, thus, far more amenable
to microelectrode-based recording techniques. Furthermore, protozoans
can be cultured easily and are more amenable to genetic and molecular
analyses.