Effects of preganglionic sympathectomy on peptides in the rat superior cervical ganglion

A NOVEL method to selectively lesion preganglionic sympathetic neurones has been combined with immunohistochemistry to study the expression of peptides in the rat superior cervical ganglion (SCG). Thus, systemic administration of monoclonal antibodies against acteylcholinesterase (AChE) caused a marked reduction in the number of enkephalin (ENK)-positive fibres and a total disappearance of fibres immunoreactive for calcitonin gene-related peptide (CGRP) and AChE in the SCG. A marked increase in the number of galanin/galanin message-associated peptide (GAL/GMAP)-immunoreactive cell bodies was also observed. The present results indicate that probably all CGRP and most ENK containing fibres in the rat SCG are of preganglionic origin and that peptides not normally expressed in SCG neurones, e.g. GAL and GMAP, can be upregulated after deafferentation.