There are generally three seperate bundles of nerve fibers that
run through the gill filament of Corbicula
fluminea. One set is generally assiciate intimately with the
frontal cirrus cell. The other two are
associated with the lateral cells.
There is a larger bundle at the base of the lateral cell, and
a smaller bundle nearer the eu-lateral-frontal
cell. It is presumed that these nerve fibers associated with
the lateral cells in some way arbitrate the metachronal wave activity
manifested by the cilia of these cells. The function of the nerve
fibers associated with the frontal cirrus cell, and why they are
partitioned off from the other apical cells of the filament, is
unknown at this time.
Below are images of the nerve bundles decribed above.
1.
A TEM of the nerve fibers running along the base of the frontal cirrus cell of Corbicula fluminea.
Note that the processes of the frontal cirrus cell completly
surround the nerve fibers. These nerve fibers are isolated from
the frontal cells and the eu-latero-frontal
cells.
2.
A TEM of the nerve fibers that are found associate with the
lateral cells in the gill of Corbicula
fluminea. This micrograph shows the nerve fiber bundle associated
with the base of the lateral cell (arrow).