Chronic drug infusion into the scala tympani of the guinea pig cochlea.

This research describes a unique, effective and inexpensive delivery system to provide discrete quantities of drugs on a chronic basis to the inner ear. The amount of the drug administered and specific timing of each administration are under investigator control. A micro-injection system mounted atop an animal's head is shown to permit repeated application of agents which effectively block neural responsiveness (tetrodotoxin) on a daily basis for periods up to 2 weeks. Cannulation of the inner ear and chronic delivery of control substances (artificial perilymph) do not affect function. This system may be used to administer drugs to other compartments of the body (e.g., the brain) on a chronic basis for neurophysiologic and neuropharmacologic investigations.