Table 3.

Comparison of motif studies in the C. elegans connectome

Chemical or electrical synapses?	Size of motifs (number of nodes)	What is signed?	Basis of signing	Reference
Both	3 and 4	Nothing	No signs	[10]
Chemical	3 and 4	Nothing	No signs	[13]
Both	3, 4, and 5	Edges	Connection type (electrical and/or chemical synapses)	[16]
Chemical	3	Nodes	Primary neurotransmitters	[17]
Both	3 and 4	Nodes	Neuron modality	[18]
Chemical	3 (partly 2)	Edges	Predicted synaptic polarity	This work

There were multiple motif studies on the C. elegans connectome. Some of them were signed analyses that labeled the network’s nodes or edges. However, our study is the first to use synaptic polarities for signed motif analysis