Active Ion Transport from the Scala Vestibuli into the Scala Media: Participation therein of Reissner's Membrane and its Blockade

The effect of G-strophantin and 2.4-dinitrophenol introduced into the scala vestibuli of 24 guinea pigs was studied by measuring endocochlea and microphonic potentials (EP and MP) which indicate ion transport and the activity of hair cells. MP were evoked by tones of 500, 1000 and 2000 c/sec. and an intensity of 60 dB. MP were always found to change together with EP but in dependence on changes of EP. Inhibition of ion transport with G-strophantin introduced into the scala vestibuli decreased EP to nearly zero while 2.4-dinitrophenol even caused EP to show negative values which in part represent the diffusion potential of a certain ionic difference between the cochlear duct and the surroundings. It is concluded that not only the stria vascularis, but also Reissner's membrane, participate in active ion transport between the cochlear duct and its surroundings. The active ion transport is a source of EP.