Immunocytochemical demonstration of 5-hydroxytryptamine (serotonin) in the nervous system of the liver fluke,Fasciola hepatica (Trematoda, Digenea)

Abstract
The localisation and distribution of 5-hydroxytryptamine (5-HT or serotonin) in the nervous system ofFasciola hepatica has been determined by an indirect immunofluorescence technique. Cell bodies and nerve fibres immunoreactive to 5-HT are present in the anterior ganglia, and the longitudinal nerve cords and their commissures in the central nervous system. In the peripheral nervous system, similar immunoreactivity occurs in the nerve plexuses supplying the sub-tegumental muscle layers and the muscular lining of various reproductive ducts, including the ootype, uterus and cirrus pouch. The significance of these results in the light of previous studies on the role of 5-HT inF. hepatica is discussed.