Centro de Ciencias do Mar 1 article published in JoVE Environment Extracellular Multi-Unit Recording from the Olfactory Nerve of Teleosts Peter Hubbard1, Zélia Velez1,2 1Centro de Ciências do Mar, 2Universidade do Algarve Extracellular multi-unit recording from the olfactory nerve is a sensitive, robust and reproducible method for assessing olfactory sensitivity in marine fish. It records primary sensory input and is independent of external salinity.