This is a proposal to expand knowledge of the ontogeny of response selectivity for behaviorally relevant sounds in the mammalian central auditory system. Developmental studies of language acquisition in human neonates, and song acquisition in birds strongly suggest the presence of an innate neural """"""""template"""""""" or """"""""blueprint"""""""" that guides the development of neural substrates that serve to direct attention towards sounds that are of behavioral significance. These studies further suggest that an auditory system is not a """"""""blank slate"""""""" prior to experience, but is instead biased to wire itself in a species-specific, adaptive fashion. Little is known, however, of the genetic contribution to the underlying neural substrates.
One aim of the proposed studies is to determine the ontogeny of response selectivity for the echolocation pulse at the midbrain and cortical levels of the pallid bat auditory system. The development of response selectivity for the downward FM sweep of the echolocation pulse will be examined from the time juvenile bats first develop a representation of their full audible range, to the time they beginning using echolocation. To separate the contributions of genes and experience, these studies will be conducted in bats reared in a normal social and acousticenvironment, and bats deprived of experience with the echolocation pulse.
A second aim examines response selectivity in normal adult bats to (1) determine the response selectivity for the echolocation pulse at two levels of the auditory system, (2) examine the mechanisms that underlie selectivity for various dimensions of the echolocation pulse, and (3) establish a reference for assessing the maturation of selectivity in developing bats. The pallid bat central auditory system exhibits an extreme degree of selectivity for the echolocation pulse, which provides clear physiological probes with which to measure the maturation process. In lieu of our current inability to study the ontogeny of the mechanisms underlying speech processing in humans, the proposed studies offer an opportunity to examine the development of response selectivity for frequency modulated, speech-like signals at two levels of a mammalian auditory system.

Agency
National Institute of Health (NIH)
Institute
National Institute on Deafness and Other Communication Disorders (NIDCD)
Type
Research Project (R01)
Project #
5R01DC005202-03
Application #
6693369
Study Section
Special Emphasis Panel (ZRG1-IFCN-5 (08))
Program Officer
Luethke, Lynn E
Project Start
2002-02-01
Project End
2006-12-31
Budget Start
2004-01-01
Budget End
2004-12-31
Support Year
3
Fiscal Year
2004
Total Cost
$191,783
Indirect Cost
Name
University of Wyoming
Department
Zoology
Type
Schools of Arts and Sciences
DUNS #
069690956
City
Laramie
State
WY
Country
United States
Zip Code
82071
Razak, Khaleel A; Fuzessery, Zoltan M (2015) Development of echolocation calls and neural selectivity for echolocation calls in the pallid bat. Dev Neurobiol 75:1125-39
Williams, Anthony J; Fuzessery, Zoltan M (2011) Differential roles of GABAergic and glycinergic input on FM selectivity in the inferior colliculus of the pallid bat. J Neurophysiol 106:2523-35
Fuzessery, Zoltan M; Razak, Khaleel A; Williams, Anthony J (2011) Multiple mechanisms shape selectivity for FM sweep rate and direction in the pallid bat inferior colliculus and auditory cortex. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 197:615-23
Williams, Anthony J; Fuzessery, Zoltan M (2010) Facilitatory mechanisms shape selectivity for the rate and direction of FM sweeps in the inferior colliculus of the pallid bat. J Neurophysiol 104:1456-71
Razak, Khaleel A; Fuzessery, Zoltan M (2010) GABA shapes a systematic map of binaural sensitivity in the auditory cortex. J Neurophysiol 104:517-28
Razak, Khaleel A; Fuzessery, Zoltan M (2010) Experience-dependent development of vocalization selectivity in the auditory cortex. J Acoust Soc Am 128:1446-51
Razak, Khaleel A; Fuzessery, Zoltan M (2010) Development of parallel auditory thalamocortical pathways for two different behaviors. Front Neuroanat 4:
Razak, Khaleel A; Zumsteg, Terese; Fuzessery, Zoltan M (2009) Development of auditory thalamocortical connections in the pallid bat, Antrozous pallidus. J Comp Neurol 515:231-42
Razak, Khaleel A; Fuzessery, Zoltan M (2009) GABA shapes selectivity for the rate and direction of frequency-modulated sweeps in the auditory cortex. J Neurophysiol 102:1366-78
Razak, Khaleel A; Richardson, Marlin D; Fuzessery, Zoltan M (2008) Experience is required for the maintenance and refinement of FM sweep selectivity in the developing auditory cortex. Proc Natl Acad Sci U S A 105:4465-70

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