We have taken a genetic approach to identify molecules involved in neurotransmission. We identified several previously unidentified genes in a behavioral screen for mutants defective in synaptic function. Among these was ric-5(n1337). When touched on the head, ric-5(n1337) mutants move backwards in a jerky, uncoordinated fashion, and frequently coil. ric-5 maps to the cluster of LG III. To obtain putative null alleles of ric-5, a noncomplementation screen was conducted to generate additional alleles. Approximately 7000 EMS mutagenized genomes were screened, and we recovered 7 new alleles of ric-5. We mapped the position of ric-5 to the right of mec-14 and to the left of lin-39. Several other mutations resembling the ric-5 phenotype mapped to this same region. osm-13(n1602) (Josh Kaplan and Anne Hart, personal communication) mapped to this interval and we demonstrated that n1337 and n1602 failed to complement. Carl Johnson mapped ric-1(e239) to this interval, and we demonstrated that e239 and n1337 failed to complement. In light of these data, ric-5 has now been renamed ric-1. Jim Rand's laboratory has isolated 19 mutations in ric-1, bringing the total number of ric-1 alleles to 28. Microinjection of cosmid pools spanning this region weakly rescue the coiling phenotype of ric-1.