Olivocochlear bundle activity recorded in awake cats.
Multi-unit activity was recorded in awake cats from the crossed olivocochlear bundle (COCB). Miniature stainless stell concentric electrodes were chronically implanted onto the floor of the fourth ventricle of six animals. There was no activity at the electrode tip in anesthetized animals, while in awake cats a great deal of unit activity could be seen. A correlation between COCB activity and ongoing behavioral activity such as scratching, grooming, yawning, or orientation could not be established. It was found, however, that the multi-unit responses in the COCB statistically increased their firing rate during acoustic stimulation, and a 500-Hz tone was found to be most effective. The electrode locations were histologically confirmed. The present results are similar to other data that describe unit activity in the olivocochlear bundle of decerebrate cats. The capacity to record from this fiber tract in awake animals, however, provides a new tool for studying the peripheral efferent pathway of the auditory system.
D000161:Acoustic Stimulation; D000818:Animals; D001522:Behavior, Animal; D002415:Cats; D003056:Cochlear Nerve / Q000502:physiology*; D004567:Electrodes, Implanted; D005071:Evoked Potentials; D009043:Motor Activity; D009476:Neurons, Efferent / Q000502:physiology; D009847:Olivary Nucleus / Q000502:physiology*