Anatomical and physiological evidence for electroreception in larval lampreys.

In larval lampreys, the superficial ophthalmic, buccal, and recurrent rami of the anterior lateral line nerve project to the dorsal nucleus of the ipsilateral medulla; the posterior lateral line nerve projects to the medial nucleus bilaterally. The recurrent ramus is the largest source of afferents to the dorsal nucleus. Extracellular recordings from recurrent afferents in the trunk lateral line nerve indicate larval lampreys are sensitive to weak, low-frequency electric fields. Cathodal (outside negative) fields are excitatory; anodal fields are inhibitory.