Dynamics of the flow of perilymph in the cochlea of the guinea pig.

The dynamics of perilymph flow in the cochlea was studied in guinea pigs. After placement of sodium chloride crystals on the round window membrane, the potassium ion concentration in the scala vestibuli in the basal turn does not change. The potassium ion concentrations in the scala tympani in the basal turn increases rapidly, while the potassium ion concentration in the scala tympani in the third turn increases slowly and to a lesser extent. The cochlear microphonic potential decreases in the basal turn and to a lesser extent in the third turn. After placement of sodium chloride on the fenestra in the scala tympani of the third turn, the chochlear microphonic potential in the basal turn does not change. These data lend support to the theory of longitudinal flow of perilymph in the scala tympani.