FIGURE 2.

Fish olfactory system. Primary projections from olfactory sensory neurons to the olfactory bulb or telencephalon are depicted in purple. Secondary olfactory projections from the olfactory bulb to the telencephalon and diencephalon are depicted in green. A putative olfacto-motor pathway connecting the posterior tubercle to executive motor centers in the mesencephalon, described in lampreys, is depicted in red. Solid lines represent connections described in zebrafish. Dotted lines represent connections described in other fish species. OE: olfactory epithelium, OB: olfactory bulb, TE: telencephalon, Dp: dorsal-posterior part of the telencephalon, Hb: habenula, Vv: ventral nucleus of the ventral telencephalon, OT: optic tectum, PT: posterior tubercle, HT: hypothalamus, CB: cerebellum, MLR: mesencephalic locomotor region; RST: reticulo-spinal tract, SC: spinal cord.