Title :
Acclimation to Chronic Constant-Rate Peripheral Stimulation Provided by a Vestibular Prosthesis
Author :
Merfeld, D.M. ; Wangsong Gong ; Morrissey, J. ; Saginaw, M. ; Haburcakova, C. ; Lewis, R.F.
Author_Institution :
Jenks Vestibular Physiol. Lab., Massachusetts Eye & Ear Infirmary, Boston, MA
Abstract :
We are developing two types of vestibular prosthetics that electrically stimulate afferent neurons. One type replaces absent sensory function by providing stimulation that modulates above and below a baseline established with the head stationary. The other type provides constant stimulation and is turned on only when necessary, for example, to override unnatural variations like those experienced by patients suffering from Meniere´s syndrome; this prosthesis does not provide motion information. Both prostheses require neural plasticity, which we investigated by providing chronic constant-rate stimulation to semicircular canal neurons in three guinea pigs. The stimulation was alternately switched on or off for eight consecutive weeks before being switched daily. A brisk horizontal nystagmus was measured when the stimulation was first turned on and then dissipated over the course of a day. The nystagmus demonstrated an after-effect in the opposite direction when the stimulation was turned off. The nystagmus that we measured after just a few (2 to 5) off-to-on transitions returned to baseline more rapidly than when first turned on. In fact, after many such off-to-on or on-to-off transitions, little nystagmus was evoked by turning the stimulation on or off. These findings show that the brain acclimates to constant-rate stimulation
Keywords :
bioelectric phenomena; brain; neurophysiology; prosthetics; Meniere´s syndrome; absent sensory function; afferent neurons; brain; chronic constant-rate peripheral stimulation; guinea pigs; neural plasticity; nystagmus; semicircular canal neurons; vestibular prosthesis; Ear; Electrical stimulation; Head; Irrigation; Neural prosthesis; Neurons; Physiology; Prosthetics; Pulse modulation; Rotation measurement; Adaptation; VOR; guinea pig; neural prosthesis; vestibular implant; vestibulo-ocular reflex; Acclimatization; Animals; Electric Stimulation; Electric Stimulation Therapy; Guinea Pigs; Male; Neuronal Plasticity; Nystagmus, Physiologic; Prostheses and Implants; Vestibule, Labyrinth;
Journal_Title :
Biomedical Engineering, IEEE Transactions on
DOI :
10.1109/TBME.2006.883645