Enables several functions, including NAD+ nucleosidase activity; enzyme binding activity; and identical protein binding activity. Involved in several processes, including NAD catabolic process; defense response to other organism; and regulation of gene expression. Acts upstream of or within serotonin biosynthetic process. Located in axon cytoplasm and cell body. Expressed in head. Used to study amyotrophic lateral sclerosis. Is an ortholog of human SARM1 (sterile alpha and TIR motif containing 1).