A model for research on cochlear hypoxia.

The vessels emerging from one side of the basilar artery are supplied exclusively by the homolateral vertebral artery. Since blood flow is laminar through the vertebrobasilar system, mixing between two sides does not normally occur. Based on this fact, an experimental model for research on cochlear hypoxia is proposed and described. The animal's own blood flow in the vertebral artery is completely replaced by a stream of poorly oxygenated blood injected retrogradely through the ipsilateral axillary artery. In this way, the territory supplied by the vessels emerging from this side of the basilar artery, including the ear, is rendered hypoxic. The changes in the cochlear action potentials induced by the reduced oxygen supply are recorded by a chronically implanted electrode and analyzed.