| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Kresge Hearing Research Institute (Otorhinolaryngology), Biomedical Engineering, Electrical Engineering & Computer Science, University of Michigan, Ann Arbor, Michigan, United States
* To whom correspondence should be addressed. E-mail: dja{at}umich.edu.
The success and limitations of cochlear implants (CIs) along with recent advances in deep brain stimulation and neural engineering have motivated the development of a central auditory prosthesis. In this study, we investigated the effects of electrical stimulation of the inferior colliculus central nucleus (ICC) on primary auditory cortex (A1) activity to determine the potential benefits of an auditory midbrain implant (AMI). We recorded multi-unit activity in A1 of ketamine-anesthetized guinea pigs in response to single pulse (200 µs/phase) monopolar stimulation of the ICC using multi-site silicon-substrate probes. We then compared measures of threshold, dynamic range, and tonotopic spread of activation for ICC stimulation with that of published data for CI stimulation. Our results showed that compared to cochlear stimulation, ICC stimulation achieved: 1) thresholds about 8 dB lower; 2) dynamic ranges at least 4 dB greater; and 3) more localized, frequency-specific activation though frequency specificity was partially lost at higher stimulus levels for low frequency ICC regions. Our results also showed that stimulation of rostral ICC regions elicited lower thresholds but with greater activation spread along the tonotopic gradient of A1 than did stimulation of more caudal regions. These results suggest that an AMI may improve frequency and level coding with lower energy requirements compared to CIs. However, a trade-off between lower perceptual thresholds and better frequency discrimination may exist that depends on location of stimulation along the caudorostral dimension of the ICC. Overall, this study provides the foundation for future AMI research and development.
This article has been cited by other articles:
|
|
 |
|
  G. Czanner, U. T. Eden, S. Wirth, M. Yanike, W. A. Suzuki, and E. N. Brown Analysis of Between-Trial and Within-Trial Neural Spiking Dynamics J Neurophysiol, May 1, 2008; 99(5): 2672 - 2693. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. S. Malmierca, M. A. Izquierdo, S. Cristaudo, O. Hernandez, D. Perez-Gonzalez, E. Covey, and D. L. Oliver A Discontinuous Tonotopic Organization in the Inferior Colliculus of the Rat J. Neurosci., April 30, 2008; 28(18): 4767 - 4776. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. N. Shivdasani, S. J. Mauger, G. D. Rathbone, and A. G. Paolini Inferior Colliculus Responses to Multichannel Microstimulation of the Ventral Cochlear Nucleus: Implications for Auditory Brain Stem Implants J Neurophysiol, January 1, 2008; 99(1): 1 - 13. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. H. Lim, T. Lenarz, G. Joseph, R.-D. Battmer, A. Samii, M. Samii, J. F. Patrick, and M. Lenarz Electrical Stimulation of the Midbrain for Hearing Restoration: Insight into the Functional Organization of the Human Central Auditory System J. Neurosci., December 5, 2007; 27(49): 13541 - 13551. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. H. Lim and D. J. Anderson Spatially Distinct Functional Output Regions within the Central Nucleus of the Inferior Colliculus: Implications for an Auditory Midbrain Implant J. Neurosci., August 8, 2007; 27(32): 8733 - 8743. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. H. Lim and D. J. Anderson Antidromic Activation Reveals Tonotopically Organized Projections From Primary Auditory Cortex to the Central Nucleus of the Inferior Colliculus in Guinea Pig J Neurophysiol, February 1, 2007; 97(2): 1413 - 1427. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |
