Expression of Phox2 in identified visceral motoneurons in gastropods. (a-d) Abdominal ganglion of A. californica hybridized on whole-mounts (a: dorsal view, b: ventral view) or transverse sections (c,d) with the indicated probes. In a, the giant R2 neuron is unlabeled. Red arrowheads in c,d: small neurons co-expressing Phox2 and LUQ-1. (e-g) Consecutive sagittal sections of the right parietal ganglion of L. stagnalis hybridized with the indicated probes, after it was filled with biocytin through the internal and external right parietal nerves (g). A, anterior; D, dorsal; L, left; P, posterior; LUQ, left upper quadrant; R, right; LYCP, LYC pro-peptide; RUQ: right upper quadrant; V, ventral. Scale bars, 100 μm (a,b); 100 μm (c,d); 200 μm (e-g).