Fig. 1.

Schematic drawing of a lateral view of the brain of the sea lamprey showing the distribution of double-labelled DA-ir/GABA-ir cells (black dots) in comparison with the distribution of DA-ir cells (grey dots). M1-3 and MI, giant Müller cells; DHyp, dorsal hypothalamus; Hyp, hypophysis; LP, lateral pallium; Mm, mammillary nucleus; MP, medial pallium; OB, olfactory bulbs; ON, optic nerve; OT, optic tectum; P, pineal organ; PCN, postoptic commissure nucleus; PON, preoptic nucleus; PoC, postoptic commissure; Pp, parapineal organ; Pt, pretectum; PTh, prethalamus; PtN, paratubercular nucleus; Rh, rhombencephalon; SC, spinal cord; ST, striatum; Th, thalamus; TrN, trigeminal nucleus; TS, torus semicircularis; VIS, ventral isthmus; Vhyp, ventral hypothalamus. Scale bar: 1 mm.