Extended Data Fig. 9: Innervation of body-wall muscle and definition of motor neurons.

a, Fraction of synaptic output that is onto muscle for the neuron classes that make neuromuscular junctions. With the exception of IL1, classes for which greater than 30% of their chemical output is onto muscle are classified as motor neurons (mn). IL1 neurons—which are classified as sensory neurons (sn)—have clear sensory endings and sensory function; they are sensory–motor neurons, but we do not use that classification here. VC and HSN—hermaphrodite-specific neurons—innervate egg-laying muscles and have traditionally been considered motor neurons. The remaining neurons are classified as interneurons. Neurons that have previously been categorized as interneurons are indicated by a dagger. Neurons that have previously been categorized as motor neurons are indicated by an asterisk. b, Fraction of the input to the body-wall muscles of the head region and the remainder of the body that comes from neurons of various classes.