Distribution of catecholamine(s) in the nervous system of a mermithid nematode, Romanomermis culicivorax.

The nervous system of the mermithid nematode Romanomermis culicivorax was investigated at different developmental stages for the distribution of catecholamine(s). The catecholaminergic nervous system increased in complexity during development. In the adult nematode, catecholamine(s) occurred in the nerve ring and associated ganglia, cephalic nerves, ventral and dorsal nerve cords and mid-body region ganglia. The distribution of catecholaminergic ganglia in the tail region was different for each sex. The tail region of males contained 16-20 catecholaminergic ganglia, whereas the tail of females contained only 2 ganglia. The catecholamine widely distributed throughout the nervous system of R. culicivorax is not dopamine, since immunoreactivity to dopamine was observed only in the amphids. The results suggest that the catecholamine(s) is widely distributed within the nervous system of R. culicivorax and might function as a neurohormone or neurotransmitter in controlling physiological and developmental processes.