title: Immunocytochemical Localization of Glucagon-Related Peptides in the Cerebral Ganglion of the Protochordate Ascidian, Styela plicata.
abstract: Abstract The central nervous system of the protochordate ascidian Styela plicata has been investigated by means of immunocytochemical techniques in order to localize peptides of the glucagon/secretin family. In particular, glucagon- and peptide histidine isoleucine-containing neurons were localized in the cortex of the cerebral ganglion, and numerous nerve cell bodies containing vasoactive intestinal polypeptide occurred mainly in the medullary zone. Moreover, coexistence of glucagon/peptide histidine isoleucine and glucagon/vasoactive intestinal polypeptide was detected in a few cortical neurons. The localization of peptide histidine isoleucine-like peptides in the central nervous system and alimentary tract supports the occurrence of a 'brain-gut axis' in protochordates as well as in vertebrates and some invertebrates, while glucagon- and vasoactive intestinal polypeptide-like substances can be considered exclusively as neuropeptides.
authors.affiliation: Istituto di Anatomia Comparata, Università di Genova, Viale Benedetto XV, 5, 16132 Genova, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Pestarino