Artifact-free application of drugs into the avian endolymphatic space

A push-pull system is described that allows artifact-free application of drugs into very small volumes such as, e.g., the endolymphatic space of the inner ear. The system consists of two syringes, the pistons of which are fixed together and driven by an Oriel motordrive. The syringes are connected to the pipette holders and microcapillaries by PVC tubes. One capillary is used to expel a certain volume, whilst the other one aspirates the same volume. A balanced exchange of fluids within a given space without an overall change in volume is therefore possible.