RIC-8 immunoreactivity observed throughout the nervous system in both juvenile and adult worms. In juveniles, but not adults, however, immunoreactivity was observed around the nuclei of many nonneuronal cells, including germ cell nuclei. Both neuronal and nonneuronal RIC-8 staining were absent in animals stained with a RIC-8 preabsorbed antibody preparation. Within the nervous system, RIC-8 appears to be present in most or all neurons, including those comprising the ventral nerve cord, although the amount of staining varied greatly between individual neurons. Observed RIC-8 staining in neuronal processes, including strong staining of amphid dendritic processes and weaker staining at some cholinergic synapses in the ventral nerve cord, as well as the axonal processes of the nerve ring.