Some details of muscles innervations by FMRF-like nerve elements in planarian Girardia tigrina.

The study is dedicated to an identification of specific FMRF immunoreactivity in planarian (Girardia tigrina) with special attention to the FMRF-like neuropeptides location near muscle filaments. Using of whole mounts in conjunction with a confocal laser scanning microscopy reveals close spatial relationship of FMRF-immunopositive(-IP) nerves and planarian musculature. Morphological data provide an evidence for FMRF-like peptides participation in the innervations of planarian muscles. The results indicate that the larger part of muscular structures and organs (pharynx, mouth opening, body wall, and tail) of planarian body are deeply supplied by FMRF-IP nerve elements. Such observation of the peptidergic FMRF-IP neurons and its processes in vicinity of the muscle fibers can indicate an important role of the neuropeptides in the regulation of planarian muscle function. [ABSTRACT FROM AUTHOR]