Development of an implantable, multielectrode array has made it possible to record chronically, over periods of several weeks, from sensory fibers of taste nerves that innervate the tongue. In the current proposal, the electrode array will be used to systematically test hypotheses about neural discharge properties of peripheral taste fibers over long time frames that encompass numerous cycles of taste bud cell turnover, and synapse remodeling. In addition, the multielectrode recording device will be progressively refined to improve and expand its range of capabilities. The rat chorda tympani nerve will be dissected and implanted with the multielectrode array through which taste nerve fibers regenerate. Subsequently, recordings will be made from the same single fiber, or sets of fibers, for weeks.
In Specific Aim 1, chronic recordings from single taste fibers of the chorda tympani nerve will be used to test the hypotheses that response characteristics of taste fibers, and receptive field properties, remain stable during cycles of taste bud cell turnover and synapse remodeling.
In Specific Aim 2, simultaneous recordings from several individual fibers will be studied over weeks to test the hypothesis that there is a unique pattern of fiber activity for separate chemical qualities, and that the pattern remains stable over time.
In Specific Aim 3, an implantable telemetry system will be used with the multielectrode array to record from chorda tympani fibers in awake rats and investigate the pattern of neural activity during feeding and drinking. The implantable, multielectrode recording array and its further refinement make possible tests of hypotheses about basic taste neurobiology that could not be resolved with previous neurophysiological techniques. Also, studies of taste fiber responses in behaving animals become feasible with the implantable device. Furthermore, continued refinement of, and experiments with, the implantable electrode array can lead to potential applications as a neural prosthesis in regeneration and restoration of sensory and motor function after trauma or disease.

Agency
National Institute of Health (NIH)
Institute
National Institute on Deafness and Other Communication Disorders (NIDCD)
Type
Research Project (R01)
Project #
5R01DC004198-04
Application #
6523487
Study Section
Special Emphasis Panel (ZRG1-IFCN-4 (01))
Program Officer
Davis, Barry
Project Start
1999-09-29
Project End
2004-08-31
Budget Start
2002-09-01
Budget End
2003-08-31
Support Year
4
Fiscal Year
2002
Total Cost
$246,692
Indirect Cost
Name
University of Michigan Ann Arbor
Department
Biology
Type
Schools of Dentistry
DUNS #
791277940
City
Ann Arbor
State
MI
Country
United States
Zip Code
48109
Mohseni, Pedram; Najafi, Khalil (2006) A 1-MHz, 5-Kb/s wireless command receiver for electronic site selection in multichannel neural biopotential recording. Conf Proc IEEE Eng Med Biol Soc 1:6241-4
Mohseni, Pedram; Najafi, Khalil (2005) A 1.48-mW low-phase-noise analog frequency modulator for wireless biotelemetry. IEEE Trans Biomed Eng 52:938-43
Mohseni, Pedram; Najafi, Khalil; Eliades, Steven J et al. (2005) Wireless multichannel biopotential recording using an integrated FM telemetry circuit. IEEE Trans Neural Syst Rehabil Eng 13:263-71
Mohseni, Pedram; Najafi, Khalil (2004) A fully integrated neural recording amplifier with DC input stabilization. IEEE Trans Biomed Eng 51:832-7
Shimatani, Yuichi; Nikles, Stefan A; Najafi, Khalil et al. (2003) Long-term recordings from afferent taste fibers. Physiol Behav 80:309-15