Blink reflex elicited by auditory stimulation in the rabbit.

The pathway of the blink reflex, elicited by auditory stimulation, was investigated electrophysiologically. The reflex was recorded as microvibrations of the eyelid and was named the auditory-evoked eyelid microvibration (AMV). Pharmacophysiological studies suggest that AMV is closely related to the midbrain reticular formation and studies of electrical lesions in the midbrain reticular formation support this. Lesions in several parts of the central nervous system provide evidence that the inferior colliculus has an important role in AMV, and the cerebral cortex may have an inhibitory influence. Studies of brainstem transections indicate that the reflex pathway of AMV exists between the lower midbrain and the upper medulla. Because of its ease and simplicity, AMV is believed to be a useful test for evaluation of the function of the brainstem.