Further studies of the membrane potential of the stria cells of the guinea pig in vitro.

Negative membrane potentials from the stria vascularis of the guinea pig have been recorded in vivo. Stable negative membrane potentials from the stria cells have also been recorded for as long as 2 minutes in vitro. They varied from -20 mV to -49 mV, irrespective of whether the stria vascularis was immersed in Ringer's solution for in K-Ringer's solution (approximately to the composition of an endolymph). Labelling of the inserted stria cells from which the membrane potential had been recorded demonstrated that the microelectrode tip was inside the cell. These cells will continue to show electrical activity for some time when immersed in suitable media.