Abstract

: Oscillation occurs widely in the nervous system but its functional significance is largely unknown. The goal oi the proposed research is to advance our understanding of the origin and functional significance of oscillation (particularly fast oscillation) in the auditory system. Pilot studies in the inferior colliculus [1C] of frogs and echolocating bats have revealed that in response to brief tone pips some IC neurons display rapid oscillatory discharges and/or paradoxical latency shift. Further, there are indications that the oscillatory discharge is presumably due to unit's intrinsic resonance and responsible for creating paradoxical latency shift, a phenomenon previously shown to be important for time domain analysis. These findings suggest that rapid oscillation in the IC may be involved in temporal processing.
Three specific aims will be addressed.
Aim #1 will determine how prevalent is oscillation in the IC and the stimulation condition under which oscillatory discharges and/or paradoxical latency shift occur. Single unit recordings will be made from the IC to test two working hypotheses: (i) IC neurons exhibit oscillatory discharges when they are appropriately stimulated, (ii) oscillatory discharge is more robust when GABAergic inhibition is suppressed.
Aim #2 is to determine the functional significance of oscillatory discharges in acoustic signal processing. Physiological experiments will be made from single units in the IC to test the hypothesis that oscillatory discharges play an important role in temporal processing.
Aim #3 is to test the hypothesis that membrane of some IC neurons exhibits intrinsic resonance and this resonance is a foundation for oscillatory discharge and/or paradoxical latency shift. In-vitro intracellular recordings will be made from brain slices to ascertain that some IC neurons exhibit intrinsic resonances under low Ca concentration in the bath. Additionally, in-vivo intracellular recordings will be made from single neurons in the IC that display paradoxical latency shift (as characterized extracellularly) to determine whether this property is created by oscillation in membrane potential.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Institute on Deafness and Other Communication Disorders (NIDCD)
Type
Research Project (R01)
Project #
5R01DC004998-05
Application #
6930997
Study Section
Special Emphasis Panel (ZRG1-IFCN-6 (01))
Program Officer
Luethke, Lynn E
Project Start
2001-09-10
Project End
2007-07-31
Budget Start
2005-08-01
Budget End
2006-07-31
Support Year
5
Fiscal Year
2005
Total Cost
$238,647
Indirect Cost

  Institution

Name
University of Illinois Urbana-Champaign
Department
Physiology
Type
Schools of Arts and Sciences
DUNS #
041544081
City
Champaign
State
IL
Country
United States
Zip Code
61820

  Publications

Yang, S; Yang, S; Cox, C L et al. (2012) Cell's intrinsic biophysical properties play a role in the systematic decrease in time-locking ability of central auditory neurons. Neuroscience 208:49-57
Goense, Jozien B M; Feng, Albert S (2012) Effects of noise bandwidth and amplitude modulation on masking in frog auditory midbrain neurons. PLoS One 7:e31589
Feng, Albert S (2011) Neural mechanisms of target ranging in FM bats: physiological evidence from bats and frogs. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 197:595-603
Melendez, Karla V; Feng, Albert S (2010) Communication calls of little brown bats display individual-specific characteristics. J Acoust Soc Am 128:919-23
Yang, Sungchil; Lin, Wenyu; Feng, Albert S (2009) Wide-ranging frequency preferences of auditory midbrain neurons: Roles of membrane time constant and synaptic properties. Eur J Neurosci 30:76-90
Gridi-Papp, Marcos; Feng, Albert S; Shen, Jun-Xian et al. (2008) Active control of ultrasonic hearing in frogs. Proc Natl Acad Sci U S A 105:11014-9
Feng, Albert S; Narins, Peter M (2008) Ultrasonic communication in concave-eared torrent frogs (Amolops tormotus). J Comp Physiol A Neuroethol Sens Neural Behav Physiol 194:159-67
Yang, Sungchil; Feng, Albert S (2007) Heterogeneous biophysical properties of frog dorsal medullary nucleus (cochlear nucleus) neurons. J Neurophysiol 98:1953-64
Wang, Xinming; Galazyuk, Alexander V; Feng, Albert S (2007) FM signals produce robust paradoxical latency shifts in the bat's inferior colliculus. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 193:13-20
Suthers, Roderick A; Narins, Peter M; Lin, Wen-Yu et al. (2006) Voices of the dead: complex nonlinear vocal signals from the larynx of an ultrasonic frog. J Exp Biol 209:4984-93

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