Vestibular Activity at Experimental Variation of Labyrinthine Pressure

Abstract

After proving elasticity within the walls of the membranous labyrinth in a previous paper, the same technique was now used for recording vestibular activity at different endolymphatic pressures. When the intralabyrinthine pressure was increased by instillation of fluid via the posterior vertical canal the activity in the horizontal ampullar nerve showed extensive variations lasting about as long as the saccule was changing its volume. After this change the activity resumed the level found at normal pressure. The rotatory responses at these positive pressures were largely the same as those found at the zero-levels. At pressures below the zero-level the rotatory response was nearly always abolished. Some membrane properties were discussed in relation to electrolyte ion concentrations in the perilymph. The findings were discussed in relation to the pathophysiology of Meniere's disease.