Electroencephalographic studies on olfactory discrimination ni adult spawning salmon

1. 1. When the nasal sac of spawning salmon is irrigated with water from the spawning site a high amplitude electroencephalographic response of characteristic pattern may be recorded from the olfactory bulb. 2. 2. This electrical response is specific in the sense that it cannot be evoked by water from spawning sites of other groups of breeding salmon. 3. 3. Weaker, but clear responses could be evoked by waters (a) traversed by the fish migrating toward the spawning site, (b) from the by-passed branch of a stream near the spawning site and (c) from a point upstream of the spawning site.